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The objective of this study was to investigate the immediate and carryover effects of imposing two post-grazing sward heights (PGSH) for varying duration during early lactation on sward characteristics and dairy cow production. The experiment was a randomised block design with a 2×2 factorial arrangement of treatments. A total of 80 spring-calving (mean calving date – 6 February) dairy cows were randomly assigned, pre-calving, to one of the two (n=40) PGSH treatments – S (2.7 cm) and M (3.5 cm) – from 13 February to 18 March, 2012 (P1). For the subsequent 5-week period (P2: 19 March to 22 April, 2012), half the animals from each P1 treatment remained on their treatment, whereas the other half of the animals switched to the opposing treatment. Following P2, all cows were managed similarly for the remainder of the lactation (P3: 23 April to 4 November, 2012) to measure the carryover effect. Milk production, BW and body condition score were measured weekly, and grass dry matter intake (GDMI) was measured on four occasions – approximately weeks 5, 10, 15 and 20 of lactation. Sward utilisation (above 2.7 cm; P1 and P2) was significantly improved by reducing the PGSH from 3.5 (0.83) to 2.7 cm (0.96). There was no effect of PGSH on cumulative annual grass dry matter (DM) production (15.3 t DM/ha). Grazing to 2.7 cm reduced GDMI by 1.7 and 0.8 kg DM/cow in P1 and P2, respectively, when compared with 3.5 cm (13.3 and 14.0 kg/cow per day, respectively). Cows grazing to 2.7 cm for both P1 and P2 (SS) tended to have reduced cumulative 10-week milk yield (−105 kg) and milk solids yield (−9 kg) when compared with cows grazing to 3.5 cm for both periods (MM; 1608 and 128 kg/cow, respectively). Treatments that alternated PGSH at the end of P1, SM and MS had intermediate results. There was no interaction between P1 and P2 treatments. There was also no carryover effect of early lactation grazing regime on milk and milk solids production in P3, given the reduction in early lactation milk yield. The results indicate that the diet of dairy cows should not be restricted by imposing a severe PGSH for all of the first 10 weeks of lactation, cows should graze to 3.5 cm for at least 5 of these weeks.

In early lactation, the energy requirement of the dairy cow often cannot be covered due to a limited feed intake. The resulting energy deficit can have a negative influence on the health and fertility of the cow. The energy balance can be calculated directly from energy requirement and energy intake, but the collection of the necessary information is challenging under on-farm conditions. Alternatively, the energy balance can also be predicted from blood and milk variables. The result of this research should answer the question, whether the content of ß-hydroxy-butyric acid (BHB) and non-esterified fatty acids from blood samples collected at certain points in the lactation phase can describe the energy balance better than average weekly milk variables, i.e. fat content, protein content and fat to protein ratio (FEQ). The aim of this study was also to characterize the effects of the number of lactation and the BCS at calving on these variables and, furthermore, the effects of energy balance, blood variables and milk solids contents on the fertility of the dairy cow. A dataset was compiled from four studies, consisting of 240 lactations from 138 dairy cows, and statistically analysed. The results showed that the milk variables had stronger relations with the measured energy balance data than the blood variables. The number of lactations had an influence on the milk protein content and the BCS at calving showed significant effects on the BHB and the milk fat contents. Cows with a more positive energy balance showed better reproductive performance. In conclusion, the observation of the milk variables will help to estimate the energy balance, but it is also important to consider other effects such as BCS at calving and lactation number. The results of this research also emphasize the importance of a monitoring of the energy balance, as an energy deficit leads to a decline in reproductive performance. [ABSTRACT FROM AUTHOR]

In order to evaluate the lipotropic potential of methionine-coline in dairy cows during the transition period, the effect of supplementation with 20 g / d of a Ruminal Degradation Protected Commercial Source (FCPDR) of methionine was evaluated, and their combinations with a choline FCPDR in doses of 60 and 120 g / day. Cows grazed kikuyo (Cenchrus clandestinus) and received a nutritional supplement between day 260 of gestation and day 20 postpartum. On day 270 of gestation and on days 10 and 20 postpartum blood samples and liver biopsy were taken, in which were quantified: Non-esterified Fatty Acids (NEFAS), β-Hydroxybutyrate (BHB) and Triglycerides; And hepatic concentrations of triacylglycerides, choline, total carnitine, free carnitine and acyl carnitine. The highest values (p < 0.05) of plasma triglycerides and the significantly lower values (p < 0.05) of AGNES and BHB were presented during the prepartum. Hepatic concentrations of triglycerides, choline and different forms of carnitine did not differ significantly between sampling periods, and were unaffected by methioninecholine supplementation. Plasma concentrations of BHB increased significantly (p < 0.05) with co-supplementation with methionine and choline, suggesting an increase in fatty acid oxidation. At relatively low concentrations of AGNES, methionine and choline are not limiting nutrients for the exportation of triglycerides from the liver to the blood, therefore under this condition no hepatic lipidosis was observed and consequently methionine-choline supplementation did not cause significant effects on hepatic triglyceride concentrations. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the diagnostic evaluation of milk lactate dehydrogenase (mLDH) and alkaline phosphatase (mALP) activities by receiver operating characteristic (ROC) analysis curve in early lactation of ewes with subclinical mastitis (SCM) and determine the correlation between number of somatic cell count (SCC) and mLDH and mALP activities. A total of 196 udder half milk samples were collected within the first 6 weeks of lambing. The SCM was determined by positive milk bacterial culture and positive California mastitis test (CMT); SCC was determined by fossomatic method and enzyme activities were determined spectrophotometrically. The mLDH and mALP of SCM cases were positively correlated with SCC values. Values of mLDH, mALP and SCC were significantly higher in SCM than non-SCM udder halves. The optimum cut-off points of mLDH and mALP activities for SCM diagnosis were determined at 203.61 (U L-1) and 329.84 (U L-1), respectively. In conclusion, SCC has positive correlation with mALP and mLDH activities in SCM ewes and mLDH and mALP activities could be considered as reliable indicators for intramammary inflammation diagnosis. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to study effects of replacement of alfalfa silage with corn silage in diets with sufficient metabolizable protein (MP) and balanced metabolizable lysine and methionine on milk production and nitrogen feed efficiency in early lactating cows. Thirty-six cows were blocked by similar body weight at calving, parity and predicted transmitting ability of milk yield, and randomly assigned into 3 dietary treatments from calving to 15 wk postpartum. Dietary treatments included 1) alfalfa silage diet (AF, 186 g/kg CP), 2) a diet replacing alfalfa silage with corn silage and supplemented with rumen undegradable protein and 2-hydroxyl-4-methylthino-butanoic acid (HMB) (CS-M, 160 g/kg CP), 3) CS-M + lysine−HCl (CS-ML, 160 g/kg CP). Metabolizable protein was similar among treatments and approximate 110 g/kg of DM. Metabolizable Met and Lys were 2.2 and 6.3% of MP in AF; and were 2.5 and 6.2% of MP in CS-M; and were 2.5 and 6.9% of MP in CS-ML. Dry matter intake, MP intake, body weight and body condition score were not affected by treatments. Nitrogen intake was less (∼ 100 g/d) in CS-M and CS-ML than AF, but milk yield, milk protein percentage and yield were similar among treatments. The percentage and yield of milk fat and milk fat corrected milk were greater in AF and CS-ML than CS-M. From 8 to 15 wk postpartum, CS-M had a moderate milk fat depression (milk fat < 30 g/kg). Compared with AF, CS-M and CS-ML had greater nitrogen feed efficiency and less milk urea nitrogen. Concentrations of lysine and leucine in blood were greater in CS-M and CS-ML, and valine tended to be greater in CS-M and CS-ML than AF. Overall, the replacement of alfalfa silage with corn silage in the diet with adequate MP and balanced metabolizable lysine and methionine could improve nitrogen feed efficiency without compromising milk production in early lactation. In addition, unbalanced ratio of metabolizable Lys to Met could depress milk fat percentage and yield. [ABSTRACT FROM AUTHOR]

Spray-dried plasma protein (SDP) compared with blood meal (BM) may contain various functional and active components that may benefit animal health. The objective of this experiment was to investigate the effects of feeding SDP or BM on production and blood profile in dairy cows during the transition and early-lactation periods. Seventy-two Holstein cows at 14 d before calving were used in a randomized block design. During the prepartum period, cows were fed a typical late-gestation diet containing BM (100 g/cow per day; 100BM, n = 24) or SDP (100 g/cow per day; 100SDP; n = 48). After calving, cows that were fed BM prepartum were fed a typical lactation diet formulated to provide 100 g/d of BM (100BM). Half the cows that were fed 100SDP prepartum were fed a lactation diet formulated to provide 100 g/d of SDP (100SDP; n = 24), and half were fed a diet formulated to provide 400 g/d of SDP (400SDP; n = 24) on a dry matter basis where SDP replaced BM (100SDP) or BM and soybean products (400SDP). All diets were balanced for crude protein concentration and metabolizable protein supply assuming BM and SDP were equal in rumen-degradable protein and rumen-undegradable protein. All data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) as a randomized block design where contrasts were made for 100BM versus 100SDP for prepartum variables and 100BM versus 100SDP and 100SDP versus 400SDP for postpartum variables. Prepartum supplementation of SDP had no effect on plasma fatty acids and β-hydroxybutyrate (2 d before calving). Plasma fatty acids (255 ± 29 µEq/mL) and β-hydroxybutyrate (675 ± 70 µmol/L) at 8 and 14 d of lactation were not affected by SDP in the diet. Feeding SDP at 100 g/d compared with 100BM increased or tended to increase milk fat, protein, and lactose contents for 16 wk after parturition. Providing SDP at 400 g/d in the diet increased milk yield (42 vs. 39 kg/d), energy-corrected milk (44 vs. 41 kg/d), energy-corrected milk per kilogram of dry matter intake, and yields of milk fat (1.60 vs. 1.48 kg/d), protein (1.21 vs. 1.16 kg/d), and lactose compared with 100SDP. Body weight losses tended to be lower for 100SDP compared with 100BM without a difference between 100SDP and 400SDP. Plasma histidine concentration (d 14 of lactation) was lower for SDP compared with 100BM. In addition, plasma 1-methyl-l-histidine tended to be lower as inclusion rate of SDP increased. In conclusion, SDP at 400 g/d increased milk and milk component yields without an increase in feed intake. Studies evaluating effects of functional and active compounds in SDP on gut microbiome, gut health, and immune functions may be needed to determine mode of action. [ABSTRACT FROM AUTHOR]

Main aim of this retrospective study was to determine the role of the level of meeting the requirements in net energy of lactation (NEL) and utilizable crude protein at the duodenum (uCP) in weeks 3-17 postpartum on the interval from parturition until conception (IUC) in dairy cows. We compared intakes and balances of NEL and uCP, body weight change, metabolic status, reticuloruminal pH, and serum amyloid A (SAA) as a systemic inflammation marker in 30 dairy cows differing in the IUC length (i.e., short (S; n = 8), medium (M; n = 11), and long (L; n = 11) IUC for cows confirmed pregnant within week 10 or between weeks 11 and 17 postpartum, or thereafter, respectively). Data showed that the level of meeting the requirements in NEL and uCP in weeks 3-10 postpartum was instrumental in shortening the IUC in the cows pertaining to S IUC group (P ≤ 0.03). As an average, during this period the S cows met 104 and 110% of their requirements in NEL and uCP, respectively. In contrast, the M and L cows met 96 and 95% of NEL as well as 104 and 101% of uCP requirements, respectively. The M cows showed higher milk and blood urea nitrogen (P = 0.04), and also lower SAA concentration (P = 0.05) compared to L cows. In conclusion, exceeding the requirements in both NEL and uCP in weeks 3-10 postpartum significantly shortened the IUC to less than 10 weeks. The shorter IUC in M vs L cows went along with improved protein status and lesser systemic inflammation in week 6 postpartum in these cows. [ABSTRACT FROM AUTHOR]

Shortening the dry period (DP) has been proposed as a strategy to improve energy balance (EB) in cows in early lactation. This study evaluated the effects of shortening the DP on milk yield (MY), EB and residual feed intake (RFI) in two breeds; Swedish Red (SR) and Swedish Holstein (SH). Cows were blocked by breed and parity and then randomly assigned to one of two treatments; short DP of 4 weeks (4W,n = 43) or conventional DP of 8 weeks (8W,n = 34). Cows were kept and fed under the same conditions, except for the 4 weeks when the 4W group were still lactating prepartum and thus kept with the lactating cows. Milk yield and BW were recorded and body condition score (BCS) was rated from 10 weeks prepartum to 12 weeks postpartum . Dry matter intake (DMI) was recorded for lactating cows postpartum . Milk yield was reduced by 6.75 kg/day during the first 12 weeks postpartum (P <0.001) for the 4W cows compared with 8W cows, but there was no significant difference in total MY (3724 kg compared with 3684 kg, P = 0.7) when the milk produced prepartum was included. Protein content was higher in 4W cows (3.42%) than in 8W cows (3.27%) (P <0.001) postpartum. In the 8W group, cows lost more BCS after calving (P <0.05). Cows of SR breed had higher BCS than cows of SH breed (SR = 3.7, SH = 3.2,P <0.001), but no differences in BW were found between breed and treatment. Energy balance was improved for cows in the 4W group (P <0.001), while feed efficiency, expressed as RFI, was reduced for 4W cows than for 8W cows (5.91 compared with -5.39,P <0.01). Shortening the DP resulted in improved EB postpartum with no difference between the breeds and no milk losses when including the milk produced prepartum . [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the associations of rumination time (RT) and health status with milk yield and milk composition. This study used 339 dairy cows from 4 commercial dairy farms in Ontario, Canada (first lactation, n = 107; second lactation, n = 112; ≥third lactation, n = 120). Rumination time was monitored (24 h/d) using an automated system from 1 to 28 d in milk (DIM). Cows were milked 3×/d on each farm, and 2 farms recorded milk weights at each milking to determine daily milk yield (n = 170). Cows were also monitored for milk composition (fat and protein content) 1×/wk. Last, subclinical ketosis (SCK) was diagnosed 1×/wk; cows with at least one blood sample with β-hydroxybutyrate ≥1.2 mmol/L postcalving were diagnosed with SCK. Cases of retained placenta, metritis, milk fever, or mastitis during the study period were also recorded. Cows were categorized into 1 of 4 groups: healthy cows that had no SCK or any other health issue (HLT; n = 139); cows that were treated for at least one health issue other than SCK (HLT+; n = 50); SCK cows with no other health problems during transition (HYK; n = 97); or cows that had SCK and one or more other health problems (HYK+; n = 53). All data were summarized by week across cows, and the associations between rumination time and milk yield (n = 170) and milk composition (n = 339) were modeled. Across all lactations, and including all health categories, milk yield increased by week, whereas fat and protein content both decreased by week. A positive association was found between summarized RT and milk yield in first-lactation (+0.006 ± 0.003 kg/min of RT) and second-lactation (+0.015 ± 0.004 kg/min of RT) cows from 4 to 28 DIM, as well as in ≥third-lactation cows; however, the relationship between RT and milk yield differed across weeks in those cows. A negative association between RT and milk fat content was found in ≥third-lactation cows (−0.002 ± 0.00059 percentage points/min of RT). From 4 to 28 DIM, ≥third-lactation HYK and HYK+ cows produced less protein (0.11 ± 0.051 and 0.13 ± 0.056 percentage points, respectively) than HLT cows. Over the 4-wk observation period, first-lactation HYK+ cows tended to deposit 0.11 ± 0.056 percentage points less protein in their milk compared with HLT cows. Second-lactation HYK+ cows produced less milk than HLT cows each week during early lactation. In summary, RT was positively associated with milk yield in early-lactation dairy cows, across all lactations, and negatively associated with milk fat content in ≥third-lactation cows. Further, the results showed that early-lactation cows that experience SCK, particularly with one or more other health problems, might have decreased milk yield and milk protein content. [ABSTRACT FROM AUTHOR]

The dairy industry needs evidence-based solutions to mitigate painful procedures and conditions in dairy cattle. The objective of this study was to compare the pharmacokinetic properties of orally versus subcutaneously administered meloxicam in early-lactation dairy cattle. The study was conducted at a commercial dairy herd in southwestern Ontario, Canada. Twelve postpartum cows were enrolled in the study, receiving either subcutaneous meloxicam (MET) at 0.5 mg/kg body weight (n = 6) or oral meloxicam (MOS) at a higher dose of 1.0 mg/kg body weight (n = 6) immediately following parturition. The predicted half-life (12.5 ± 2.0 vs. 28.5 ± 2.0 h), Cmax (1.59 ± 0.15 vs. 1.95 ± 0.16 μg/mL), Tmax (5.33 vs. 11.7 h), and AUC0→∞ (39.6 ± 7.4 vs. 115.6 ± 19 h * µg/mL) differed significantly between MET and MOS cows, respectively. After controlling for the treatment group, first lactation cows had a significantly higher half-life (4.1 ± 2.1 h), Cmax (0.56 ± 0.2 µg/mL), and AUC0→∞ (21.6 ± h * µg/mL) relative to second lactation or greater cows, respectively. Administration of meloxicam through the subcutaneous or oral route results in appreciable, dose-dependent systemic levels.

Modern dairy cows meet the energy demand of early lactation by calling on hormonally driven mechanisms to increase the use of lipid reserves. In this context, we recently reported that fibroblast growth factor-21 (FGF21), a hormone required for efficient use of lipid reserves in rodents, is upregulated in periparturient dairy cows. Increased plasma FGF21 in early lactation coincides with elevated circulating concentrations of glucagon (GCG) and nonesterified fatty acids (NEFA). To assess the relative contribution of these factors in regulating FGF21, two experiments were performed in energy-sufficient, nonpregnant, nonlactating dairy cows. In the first study, cows were injected with saline or GCG every 8 h over a 72-h period. GCG increased hepatic FGF21 mRNA by an average of fivefold over matched controls but had no effect on plasma FGF21. In the second study, cows were infused and injected with saline, infused with Intralipid and injected with saline, or infused with Intralipid and injected with GCG. Infusions and injections were administered intravenously over 16 h and subcutaneously every 8 h, respectively. Intralipid infusion increased plasma NEFA from 92 to 550 µM within 3 h and increased plasma FGF21 from 1.3 to >11 ng/ml 6 h later; FGF21 mRNA increased by 34-fold in liver but remained invariant in adipose tissue. GCG injections during the Intralipid infusion had no additional effects on plasma NEFA, liver FGF21 mRNA, or plasma FGF21. These data implicate plasma NEFA as a key factor triggering hepatic production and increased circulating concentrations of FGF21 in early lactation. [ABSTRACT FROM AUTHOR]

Lactation is a period, which involves important changes of energy metabolism in ruminants. Leptin and ghrelin are hormones that play a critical role in the regulation of energy homeostasis. In this study we investigated levels of leptin and ghrelin hormones, which have roles on changes of energy metabolism, during early lactation period in sheep. Leptin and ghrelin levels of 10 sheep after birth were measured at the 4th and 6th weeks of the early lactation period. Hormone measurements were analyzed with using specific commercial ELISA kits. Leptin and Ghrelin levels were significantly lower in the 4th week than in the 6th week (P<0.05). There was also a high level of significant correlation between leptin and ghrelin levels. These results have shown that leptin and ghrelin peptides play a role in metabolism in response to energy changes in the early lactation and are simultaneously decreasing or increasing. This may be related to increased energy needs, weight loss, mobilization of adipose tissue lipids, or other hormonal regulatory mechanisms involved in energy metabolism as well as birth and postpartum breastfeeding. [ABSTRACT FROM AUTHOR]

Grazing native vegetation does not satisfy the nutritional needs of the dairy goats, especially in early lactation. Therefore, there are strategies of food supplementation to increase milk production; most of the feed supplementation research has focused on meeting the needs of the drought period. However, it is necessary to evaluate whether in the rainy season the availability of forage species may cover the nutritional requirements of the goats, or at least the deficit is lower and therefore avoid unnecessary expenses in extra feeding. Therefore, the objective of this study was to evaluate the effect of pre-partum and post-partum concentrate supplementation and its effect on body weitgth, body condition, milk production and milk quality, in the early lactation and during the rainy season at the Comarca Lagunera in Northern Mexico. Method: There were used 33 adult local goats. a) Control group (control) (n = 11), which were fed exclusively with the forages collected by the animal in the grazing route. b) Pre kidding goat group (N = 11) who aditionaly to the pasture grazed were offered 500 g of commercial concentrate per animal and day, during 30 days before the kidding time and c) Postpartum group (n = 11) free pasture grazed plus 500 g of concentrate Commercial by animal and day during 30 days from the date of kidding time. The variables of body weight (PV) and body condition (CC) were measured weekly, during 14 weeks. Milk production and milk quality (Fat, Protein and Lactose) were measured weekly from the date of parturition during 8 weeks. The statistical analysis for milk production and quality variables were performed using the MIXED procedure. The PV and CC data were analyzed using the GLM procedure and the Tukey test fitted for the comparison of means was used. Concentrate consumption data were analyzed with a t-test to determine differences between supplemented groups. Results: There were no differences (p> 0.05) in the consumption of concentrate in the pre- and postpartum groups. There were found differences (p <0.05) in PV and CC prior to kidding time. Post partum the PV and CC were similar in all groups with losses until the end of the experiment. There were no differences (p> 0.05) in milk production, fat content, protein or lactose, nor effects of treatment * time interaction. Discussion: It is concluded, that supplement used one month before or after birth do not improve milk production, chemical composition of milk or body weigth from local goats in early lactation and rainy season under extensive grazing conditions in the Comarca Lagunera in northern Mexico. [ABSTRACT FROM AUTHOR]

Background: It was recently reported that dairy cows fed a polyphenol-rich grape seed and grape marc meal extract (GSGME) during the transition period had an increased milk yield, but the underlying reasons remained unclear. As polyphenols exert a broad spectrum of metabolic effects, we hypothesized that feeding of GSGME influences metabolic pathways in the liver which could account for the positive effects of GSGME in dairy cows. In order to identify these pathways, we performed genome-wide transcript profiling in the liver and lipid profiling in plasma of dairy cows fed GSGME during the transition period at 1 week postpartum. Results: Transcriptomic analysis of the liver revealed 207 differentially expressed transcripts, from which 156 were up- and 51 were down-regulated, between cows fed GSGME and control cows. Gene set enrichment analysis of the 155 up-regulated mRNAs showed that the most enriched gene ontology (GO) biological process terms were dealing with cell cycle regulation and the most enriched Kyoto Encyclopedia of Genes and Genomes pathways were p53 signaling and cell cycle. Functional analysis of the 43 down-regulated mRNAs revealed that a great part of these genes are involved in endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) and inflammatory processes. Accordingly, protein folding, response to unfolded protein, unfolded protein binding, chemokine activity and heat shock protein binding were identified as one of the most enriched GO biological process and molecular function terms assigned to the down-regulated genes. In line with the transcriptomics data the plasma concentrations of the acute phase proteins serum amyloid A (SAA) and haptoglobin were reduced in cows fed GSGME compared to control cows. Lipidomic analysis of plasma revealed no differences in the concentrations of individual species of major and minor lipid classes between cows fed GSGME and control cows. Conclusions: Analysis of hepatic transcript profile in cows fed GSGME during the transition period at 1 week postpartum indicates that polyphenol-rich feed components are able to inhibit ER stress-induced UPR and inflammatory processes, both of which are considered to contribute to liver-associated diseases and to impair milk performance in dairy cows, in the liver of dairy cows during early lactation. [ABSTRACT FROM AUTHOR]

During a three-year period (2010 to 2012) within the project BHNP (breed for health neo-partus) data on various indicators for health status were collected for 15,273 calvings of Holstein cows from seven large herds in Germany. Within our project, it was attempted to measure cell counts during the early colostral phase, i.e. within the first five days after parturition. However, due to the field study nature of the project, samples obtained varied with respect to the day collected post-partum. In total, 8,447 samples with an average collection day of 5.3 p.p. and a range between 0 to 20 days p.p. were obtained. Noting that cell counts from the early lactation in general are on a higher level than lactation cell counts, it was found that cows with cell counts above 400,000 show a drastic and highly significant increase in the probability for a later treatment for udder health. For early cell counts below 100,000, between 100,000 and 400,000, and above 400,000, probabilities for a later treatment within the first 100 days of lactation increased from 20.32%, to 23.97%, and to 37.55% based on a mixed model analysis accounting for effects of herd-year-season and parity-age-at-calving. This finding was not due to an auto-correlation as herd managers were unaware of the results from the colostral phase samples. Probabilities for later treatment also corresponded to data for culling within the lactation. Estimates of heritabilities for SCSel (Somatic cell count in early lactation) were 0.23 when data was restricted to days in milk 0 to 4 only (n = 4,006 lactations) and 0.10 for the full data set (n = 7,483). In summary, the results confirm the use of somatic cell counts from the early lactation as a potential management tool and as a new trait for genetic selection. [ABSTRACT FROM AUTHOR]

Grazing pastures to low post-grazing sward heights (PGSH) is a strategy to maximise the quantity of grazed grass in the diet of dairy cows within temperate grass-based systems. Within Irish spring-calving systems, it was hypothesised that grazing swards to very low PGSH would increase herbage availability during early lactation but would reduce dairy cow performance, the effect of which would persist in subsequent lactation performance when compared with cows grazing to a higher PGSH. Seventy-two Holstein–Friesian dairy cows (mean calving date, 12 February) were randomly assigned post-calving across two PGSH treatments (n = 36): 2.7 cm (severe; S1) and 3.5 cm (moderate; M1), which were applied from 10 February to 18 April (period 1; P1). This was followed by a carryover period (period 2; P2) during which cows were randomly reassigned within their P1 treatment across two further PGSH (n = 18): 3.5 cm (severe, SS and MS) and 4.5 cm (moderate, SM and MM) until 30 October. Decreasing PGSH from 3.5 to 2.7 cm significantly decreased milk (−2.3 kg/cow per day), protein (−95 g/day), fat (−143 g/day) and lactose (−109 g/day) yields, milk protein (−1.2 g/kg) and fat (−2.2 g/kg) concentrations and grass dry matter intake (GDMI; −1.7 kg dry matter/cow per day). The severe PGSH was associated with a lower bodyweight (BW) at the end of P1. There was no carryover effect of P1 PGSH on subsequent milk or milk solids yields in P2, but PGSH had a significant carryover effect on milk fat and lactose concentrations. Animals severely restricted at pasture in early spring had a higher BW and slightly higher body condition score in later lactation when compared with M1 animals. During P2, increasing PGSH from 3.5 to 4.5 cm increased milk and milk solids yield as a result of greater GDMI and resulted in higher mean BW and end BW. This study indicates that following a 10-week period of feed restriction, subsequent dairy cow cumulative milk production is unaffected. However, the substantial loss in milk solid yield that occurred during the period of restriction is not recovered.

The objective of this research was to determine the changes in the number of cells of white blood line and some biochemical parameters: concentration of glucose, concentration of non-esterified fatty acids (NEFA), activity of enzymes of aspartat aminotransferase (AST), alanin aminotransferase (ALT) and gamma glutamyltranferase (GGT), in 17 Holstein-Friesian breed dairy cows in peripartum period and early lactation (on d 15 prepartum, on the day of parturition and on d 15, 30, and 45 postpartum). The highest values of total leukocytes count, neutrophiles, monocytes and basophiles count were recorded on the day of parturition, and then decreased, so that the minimum value established on d 45 of lactation. The lymphocytes count was the lowest on the day of parturation, while the eosinophils and basophiles counts were significantly different in observed time intervals. The concentration of glucose ranged from 3.07 mmol/L on d 15 prepartum to 2.71 mmol/L on d 15 postpartum. A high concentration of non-esterified fatty acids (NEFA) in the postpartum period is a consequence of changes in energy balance and more intensive process of lypolisis in fat tissue, due to energy disbalance at the beginning of lactation. Established activity of enzymes AST, ALT and GGT was approximately the same in studied time intervals and was within physiological limits. The results of hematological and biochemical analysis in this paper do not indicate the development of postpartum ailments, because the investigated parameters were within physiological limits.

Objetivou-se avaliar o efeito de teores crescentes de PB na MS total da dieta (11,5; 13,0; 14,5 e 16,0%) sobre os consumos e a digestibilidade total dos nutrientes e a produção e composição do leite de vacas leiteiras no terço inicial da lactação. O experimento foi constituído de quatro períodos experimentais de 15 dias, sete para adaptação dos animais à dieta e oito para coleta de dados. Foram utilizadas oito vacas, manejadas em cochos individuais, distribuídas em dois quadrados latinos balanceados 4 × 4. Utilizou-se concentrado à base de farelo de algodão e fubá de milho (40%) e, como volumoso, cana-de-açúcar corrigida com 1% de uréia + sulfato de amônio (9:1), na proporção de 60% (% MS). Os consumos médios diários de nutrientes, exceto EE e CNF, diferiram à medida que os teores de PB da dieta aumentaram. Os teores de PB na dieta não afetaram os coeficientes de digestibilidade aparente total dos nutrientes. A produção de leite corrigida ou não para 3,5% de gordura e seus componentes (gordura, PB e lactose), expressa em g/dia, e o nitrogênio uréico no leite (NUL) tiveram efeito linear crescente, enquanto a eficiência de utilização de N sofreu efeito linear negativo dos teores de PB da dieta. A dieta com 16% PB resultou em valores numericamente maiores de consumo e produção do leite e de seus componentes se comparada às dietas com menores teores de PB.The objective of this research was to evaluate the effect of increasing levels of CP in the total DM of diet (11.5, 13.0, 14.5 and 16.0%) on the intakes and the total digestibility of nutrients and the milk production and composition of dairy cows in initial third of lactation. The research was constituted by four experimental periods of 15 days each, seven for adaptation of the animals to the diet and eight for data collection. Eight cows, individually fed, were distributed to two balanced 4 × 4 Latin squares. A cottonseed meal, ground corn-based concentrate (40%) was used and, as forage, sugar cane corrected with 1% of urea + ammonium sulfate (9:1), in the proportion of 60% (%DM). The daily average intakes of nutrients, except for EE and NFC, differed as the levels of CP increased in the diet. The protein levels in the diet did not affected the coefficients of total apparent digestibility of the nutrients. Production of fat corrected milk, 3.5% or not and its components (fat, CP and lactose), expressed in g/day, and milk urea nitrogen showed increased linear effect, while the N efficiency showed negative linear effect of the CP levels in the diet. The diet with 16% CP provided values numerically greater for intake and milk production and its components as compared to diets with lower levels of CP.

The objectives of this study were to compare the effects of post-ruminal and intravenous infusions of wheat starch or glucose (CHO) or a mixture of amino acids (AA) on milk protein yield, nitrogen utilisation, plasma metabolites and mammary extraction rate of dairy cows in early lactation. Eight cow, ruminally fistulated, was assigned to two 4 × 4 Latin squares during 14-day periods, where the last 7 days were for infusions. Infusions were: (1) starch in the abomasum (SP), (2) glucose in the blood (GB), (3) AA in the abomasum (AP), and (4) AA in the blood (AB). The experiment started 54 ± 4 days (mean ± s.e.) post partum (milk yield 33.4 ± 1.7 kg). Daily amounts of nutrients infused were 378, 365, 341, and 333 g for SP, GB, AP and AB, respectively. The cows were fed a basal diet consisting of a concentrate mixture and grass silage (55:45 on dry-matter (DM) basis), and DM intake was 17.2 kg/day. Milk production was affected by site of infusion within substrate, whereas infusion substrates within infusion site (CHO or AA) were of minor importance. Compared with SP infusion, GB infusion increased ( P 0.10) plasma glucose or insulin concentrations above that of SP infusion. Compared with the SP infusion, the GB infusion had minor effect on plasma AA. AP infusion increased ( P 0.05) on essential AA (EAA) or branched-chain AA (BCAA). Although a higher milk protein synthesis was observed for AB infusion, the mammary extraction rate was not higher ( P>0.05) than for AP infusion. Across infusion site, AP and AB infusions increased plasma concentration of EAA and BCAA, but compared with GB infusion, the mammary extraction rates tended ( P

The low efficiency of embryo production in Holstein cows during early lactation presents many challenges for animal production. To improve its efficiency, the outcomes of single GnRH injections 48 hours before each of three cycles of ovum pick up (OPU; weeks 2, 4, and 6) were compared with three cycles of unstimulated OPU (controls; weeks 1, 3, and 5) in 35 Holstein cows during 6 weeks of early lactation (40–80 days postpartum). More total follicle numbers (19.5 vs. 16.0; P < 0.05) but fewer dominant follicles (0.5 vs. 1.4; P < 0.01) were observed by ultrasound, and more cumulus–oocyte complexes were collected in a single OPU in the treatment cycles compared with controls (15.3 vs. 11.5; P < 0.05). The numbers of morphologically “good” cumulus–oocyte complexes graded A and B in the stimulated OPUs were significantly greater than in controls (2.8 vs. 1.7 and 5.8 vs. 4.2, respectively; P < 0.05). Significantly, more oocytes stained positively with brilliant cresyl blue after GnRH treatment compared with the control cycles (13.7 vs. 9.6; P < 0.05). After in vitro fertilization, embryos in the treatment cycles had improved development (P < 0.01) during each developmental stage compared with the controls (9.0 vs. 6.2 two-cell embryos; 4.7 vs. 3.0 four-cell embryos; 3.3 vs. 2.0 morulae; and 3.0 vs. 1.7 blastocysts, respectively). Moreover, there was no significant difference in pregnancy rate of the recipient cows after embryo transfer (57.1% vs. 42.1%; P > 0.05) no matter if the embryos came from the GnRH-treated cycles or not. Thus, GnRH-stimulated OPUs improved the efficiency of embryo production in Holstein cows during early lactation. This novel method for in vitro embryo production should benefit the dairy industry. [ABSTRACT FROM AUTHOR]

Economic success in dairy herds is heavily reliant on obtaining pregnancies at an early stage of lactation. Our objective in this study was to attempt to predict the likelihood of conception occurring by d 100 and 150 of lactation (days in milk, DIM) by Markov chain Monte Carlo analysis using test day milk recording data and reproductive records gathered retrospectively from 8,750 cows from 33 dairy herds located in the United Kingdom. Overall, 65% of cows recalved with 30, 46, and 65% of cows conceiving by 100 DIM, 150 DIM, and beyond 150 DIM, respectively. Overall conception rate (total cows pregnant/total number of inseminations) was 27.47%. Median and mean calving to conception intervals were 123 and 105 d, respectively. The probability of conception by both 100 DIM and 150 DIM was positively associated with the average daily milk weight produced during the fourth week of lactation (W4MK) and protein percentage for test day samples collected between 0 to 30 and 31 to 60 DIM. Butterfat percentage at 0 to 30 DIM was negatively associated with the probability of conception by 100 DIM but not at 150 DIM. High somatic cell count (SCC) at both 0 to 30 and 31 to 60 DIM was negatively associated with the probability of conception by 100 DIM, whereas high SCC at 31 to 60 DIM was associated with a reduced probability of conception by 150 DIM. Increasing parity was associated with a reduced odds of pregnancy. Posterior predictions of the likelihood of conception for cows categorized as having "good" (W4MK >30 kg and protein percentage at 0 to 30 and 31 to 60 DIM >3.2%) or "poor" (W4MK <25 kg and protein percentage at 0 to 30 and 31 to 60 DIM <3.0%) early lactation attributes with actual observed values indicated model fit was good. The predicted likelihood of a "good" cow conceiving by 100 and 150 DIM was 0.39 and 0.57, respectively (actual observed values 0.40 and 0.59). The corresponding values for a "poor" cow were 0.28 and 0.42 (actual observed values 0.26 and 0.37). Predictions of the future reproductive success of cows may be possible using a limited number of early lactation attributes. [ABSTRACT FROM AUTHOR]

Forty-eight multiparous cows were used in a randomized complete block design experiment with a 2 × 2 factorial arrangement of treatments to determine the interaction between chromium propionate (CrPr) supplementation and sources of corn varying in ruminal starch fermentability on production responses during the postpartum (PP) and carryover periods. During the peripartum period (28 d before expected parturition until 28 d PP), diets were top-dressed (20 g/d) with either CrPr (KemTRACE Chromium Propionate, Kemin Industries, Des Moines, IA; 8 mg of Cr/cow per day) or control (Con; ground corn). At parturition, cows were randomly assigned to corn treatment within CrPr and Con treatments: dry corn (DC) or high-moisture corn (HMC). Treatment combinations (CrPr/DC, CrPr/ HMC, Con/DC, and Con/HMC) were fed from parturition until 28 d PP (treatment period). Cows were fed a common diet to evaluate potential carryover effects of the treatment diets from 29 to 84 d PP (carryover period). The CrPr and corn treatments interacted over time to affect yield of 3.5% fat-corrected milk (FCM) during both the treatment and carryover periods. The CrPr/HMC treatment combination tended to increase FCM compared with Con/DC and Con/HMC by 28 d PP (57.4 vs. 48.6 and 48.5 kg/d, respectively) and increased FCM compared with Con/DC by 42 d PP (59.2 vs. 44.8 kg/d). The CrPr tended to increase milk yield (55.4 vs. 51.9 kg/d) regardless of corn source during the carryover period after treatment ceased. Daily and cumulative DMI were not affected by treatment during the PP period, but CrPr and corn treatments interacted over time to affect daily DMI during the carryover period; DMI was generally higher for CrPr/ HMC, lower for Con/DC, and intermediate for CrPr/ DC and Con/HMC from 29 to 84 d PP. Supplementation of CrPr throughout the peripartum period interacted with starch source in PP diets over time to affect production responses that were sustained after treatment application ceased. [ABSTRACT FROM AUTHOR]

Changes in metabolic functions in transition dairy cows represent a result of negative energy balance. This leads to increased lipid mobilization and ketogenesis, followed by increased concentrations of non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB). Hence, high lipid mobilization and ketogenesis modulate inflammation response and vice versa. The aim of this study was to investigate correlations between ketoprofen administration, high lipid mobilization, ketogenesis and characteristics of metabolic adaptation in cows. Ketoprofen was administered intramuscularly in the concentration of 3 mg/kg, during three consecutive days in 15 postpartum cows. The control group included 15 cows which were not treated with ketoprofen. Blood samples were taken from coccygeal vein, after calving, in the first and second week of the postpartum period. When compared with control, ketoprofen administration decrease the levels of NEFA, BHB and total bilirubin, increase levels of glucose, albumin and cholesterol. Our results showed decreased activity of AST in ketoprofen treated cows in comparison with control group. There was an increase in the intensity of lipolysis and ketogenesis in 66.7% of cows, with NEFA and BHB values over the optimal results, because ketoprofen was not applied to these animals. Cows in the control group were 2 or 2.4 times more likely to come to a state of increased lipid mobilization and ketogenesis. We have found high concordance between NEFA and BHB, and metabolic parameters. This correlation was lower in experimental group of cows hence we can conclude that the use of ketoprofen immediately after calving reduces lipid mobilization and ketogenesis during early lactation and the metabolic adaptation dependence on the intensity of these two processes. [ABSTRACT FROM AUTHOR]

The objective of the current study was to determine associations between the severity of systemic inflammation during the early postpartum period and performance, energy metabolism, and immune function in dairy cows. Cows were assigned to categorical quartiles (Q; Q1 = 0.18-0.59, Q2 = 0.60-1.14, Q3 = 1.15-2.05, and Q4 = 2.06-2.50 g of haptoglobin/L) based on the highest plasma haptoglobin (Hp) concentration measured during wk 1 postpartum. Although cows were assigned to different categories of inflammation during the postpartum period, we detected a quadratic relationship of inflammation on prepartum dry matter intake (DMI) and body weight (BW) such that cows in Q2 had lower prepartum DMI and cows in Q2 and Q3 had lower prepartum BW compared with cows in the other quartiles. We also detected a quadratic association of inflammation with postpartum DMI and BW such that cows in Q2 and Q3 also had generally lower postpartum DMI and BW compared with cows in Q1. There was a tendency for a Q x time interaction for milk yield and Q x time interactions for 3.5% fat-corrected milk and energy-corrected milk yields; quadratic relationships suggested decreased milk yield for Q2 and Q3 cows. We also found Q x parity and Q x time interactions for plasma glucose and insulin concentrations, suggesting alterations with differing degrees of inflammation. There was also a Q x time interaction for plasma nonesterified fatty acids concentration. In addition, alterations in liver triglyceride and glycogen contents for cows with inflammation as well as alterations in [1-14C]propionate oxidation in vitro were observed. Although we observed limited effects of inflammation on neutrophil and monocyte phagocytosis at d 7 postpartum, inflammation appeared to alter neutrophil and monocyte oxidative burst. Overall, cows with any degree of elevated haptoglobin in the first week after calving had alterations in both pre- and postpartum intake and postpartum metabolism. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate nutritional and metabolic status in Simmental cows during early and mid-lactation. Fifteen early lactating cows and 15 mid lactating cows were chosen for the investigation. Blood samples were collected to measure beta-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), triglycerides (TG), glucose and the activity of aspartate transaminase (AST). Early lactation as compared to mid lactating cows were found to have significantly higher (P<0.05) blood serum concentrations of NEFA, BHB and AST and lower blood serum concentrations of glucose (P<0.05) and TG (P>0.05). Significantly negative correlations were observed between BHB and glucose (P<0.01), BHB and TG (P<0.05), NEFA and glucose (P<0.05). Significantly positive correlations were observed between NEFA and BHB (P<0.05), NEFA and AST (P<0.05), glucose and TG (P<0.01). The results suggest that these parameters can serve as useful indicators of the nutritional and metabolic status of dairy cows during lactation. [ABSTRACT FROM AUTHOR]

Background: The prevalence of exclusive breastfeeding until the age of 4 months is low. One of the many factors associated with it is healthcare supports on breastfeeding. Objective: The aim of this study was to assess the effect of healthcare supports for breastfeeding on the prevalence of exclusive breastfeeding until the age 4 months. Methods: This was a cohort study including 99 infants born at 10 birth clinics in Pekanbaru City during August-December 2003. Exposure was whether mother received supports for breastfeeding. Infants were followed monthly for 4 months to assess the duration they received exclusive breastfeeding. Results: Healthcare supports for breastfeeding were significantly associated with the duration of exclusive breastfeeding, i.e. RR (95%CI): 1.66 (1.08-2.54). Variables associated with longer duration of exclusive breastfeeding were availability of rooming in and early lactation. Early formula feeding did not support exclusive breastfeeding. Other variables associated with exclusive breastfeeding were husbands’ and other family members’ supports, maternal opinion on exclusive breastfeeding and maternal occupation. Conclusion: Healthcare supports on breastfeeding were important for promoting exclusive breastfeeding.

This study aimed to quantify the mobilization of body energy of alpine goats slaughtered at fixed time intervals from parturition to 56 days of lactation. Fifty-one multiparous Alpine dairy goats were used to determine the body composition of the animals. Three goats were slaughtered to estimate the initial body composition of the animals that remained in the experiment. Forty-eight goats were assigned to a completely randomized design, and the treatments were the eight subsequent weeks of lactation (7th, ..., 56th days). Six goats were slaughtered per week. We used linear and non-linear models to analyze the variables with and without repeated measures. The animals' dry matter intake reached the maximum of 1.5 ± 0.21 kg/day at 40 ± 3 days of lactation. The milk yield reached the maximum of 2.52 ± 0.32 kg/day at 28 ± 9 days of lactation. The rate of secretion of the milk components such as fat, protein, lactose, and energy reached maximum values of 141.0 ± 17.5, 102.2 ± 16.1, 100.5 ± 24 g/day, and 9.44 ± 1.01 MJ/day at 7 ± 2, 2 ± 5, 18 ± 12, and 7 ± 2 days of lactation, respectively. Empty body mass, non-carcass components, carcass, and omental and visceral fat reduced with the advance of the lactation weeks. In conclusion, dairy goats in early lactation mobilize not only energy reserves from omental and visceral fats but also from the carcass and non-carcass components, ash, and water. The body energy of alpine goats is mobilized with higher intensity in the first eight weeks of lactation due to the more significant mobilization of omental and visceral fats (average of 130 g/day) in the empty body weight. Body energy decreased linearly, and the total amount of energy mobilized during the first eight weeks of lactation was considerable: 352MJ, with an average of 6.24 MJ/day. • The fat and protein were mobilized not only from the carcass but also from the non-carcass components. • The mass of internal fat in early lactation is very important to minimize the mobilization of tissue protein. • The mass of the internal organs was reduced by 0.72 kg/wk, which corresponds to 12.85 MJ/wk of energy. [ABSTRACT FROM AUTHOR]