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This study evaluated the effects of the dietary starch amylose/amylopectin ratio on growth performance, rumen fermentation and blood parameters, carcass characteristics and marbling score, and meat fatty acid profiles and transcriptional changes in the genes involved in the gluconeogenesis pathway in Chinese Qinchuan cattle. Forty-five cattle were randomly divided into three groups. The bulls were fed a control diet (middle amylose/amylopectin ratio=0.47) or diets with either waxy corn starch (WS) inclusion (low amylose/amylopectin ratio=0.23) or pea starch (PS) inclusion (high amylose/amylopectin ratio=0.60) for 90 days. The bulls were individually allowed to receive the diets at the daily amount of at least 2.1% of their individual BW twice daily. The bulls were weighed at 45-day intervals, and blood and rumen fluid samples were also collected at 45-day intervals. The bulls were slaughtered and longissimus thoracis (LT) samples were collected for meat quality measurements. Compared with PS, the average daily gain (ADG) and feed efficiency in control and WS were increased (P0.05) among the three groups. Compared with PS, the serum insulin concentration in WS was increased (P0.05). Chemical and physio-chemical compositions of LT did not differ (P>0.05) among the three groups. In conclusion, diets with low or middle amylose/amylopectin ratios increased the backfat thickness, and tended to improve ADG, but had no effect on other carcass characteristics, fat content in the LT, or the expression of hepatic genes related to the gluconeogenesis pathway in Chinese Qinchuan cattle.

The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves. Thirty-six newborn Holstein bull calves were assigned to 1 of 3 treatments: (1) conventional weaning (d 56) and fed a high proportion of solid feed (CWS); (2) conventional weaning (d 56) and fed a high proportion of liquid feed (CWL); (3) early weaning (d 42) and fed with a high proportion of solid feed (EWS). High-throughput sequencing of the methyl coenzyme M reductase (mcrA) gene, which encodes the α-subunit of methyl coenzyme M reductase — the enzyme that catalyzes the final step in methanogenesis was used to determine the composition and diversity of rumen methanogens. No significant difference (P>0.05) was observed for operational taxonomic units (OTUs) or richness indices, but diversity indices increased (P

The importance of nutrient provisions and weaning methods for calves has been well established over the past few years, while as increasing interest has focused on contribution of animal behavior and their overall performance in production regimes. The present study investigated the effects of feeding methods and space allowance on growth performance, individual and social behaviors in Holstein calves. Twenty-four Chinese Holstein male and female calves were allocated to either an individual or group of 6 and fed either with a bucket or a teat. Milk replacer, calf starter, and Chinese wildrye were offered during the experiment. A fecal index used in the present study was defined as the total fecal scores/total number of calves in each treatment. The results showed that there was no significant difference among the 4 treatments in terms of feed intake, body weight, average daily gain, and fecal index. For the feeding behaviors, the ingesting milk time and ingesting milk rate were significantly affected by space allowance, while the feeding methods showed a significant influence on the bunting behavior of the calves. There was no significant difference among the 4 treatments in terms of licking fixtures, self-grooming, and lying down behaviors, irrespective of the feeding method or space allowance. However, sucking an empty bucket or the teat was significantly affected by the feeding method. Several selected group behaviors were examined in the present study, and similar values for sniffing the other calves, social grooming, and cross-sucking behaviors were observed. Overall, the present study demonstrated that different feeding methods and space allowances had a significant effect on the feeding behavior of calves, while the feed intake, growth performance, health condition, individual and group social behaviors were not significantly influenced. Furthermore, under intensified production systems, Holstein calves raised in a group may obtain a similar production performance, thus reducing management input and profitability compared with those kept individually. However, there may be competition during the feeding period.

We evaluated the effects of diets with different crude protein (CP) levels on growth performance, rumen fermentation and bacterial communities in weaned Chahaer lambs. 128 weaned Chahaer lambs ((20.56±1.43) kg body weight; ram:ewe 1:1) aged (61±1.85) d were randomly allotted to one of four diets with CP content of 11.17% (T1), 12.06% (T2), 13.40% (T3) or 14.36% (T4). Ruminal fermentation parameters were measured and bacterial communities were analysed using PCR-dena-turing gradient gel electrophoresis (PCR-DGGE) and quantitative PCR. The average daily gain and feed utilization efficiency in T3 were higher than those in the other groups (P

This experiment was conducted to investigate the energy requirement of Dorper×thin-tailed Han crossbred ewes during non-pregnancy and lactation. Fifteen ewes after parturition were randomly assigned to three treatments: ad libitum (100%) feed intake and 80 or 60% ad libitum intake, and another nine non-pregnant ewes were assigned to a blank control group. Digestibility trials were performed in the non-pregnant ewes and in the lactating ewes on the 20th, 50th, and 80th d of lactation. In parallel with the digestibility trial, a respirometry experiment was conducted to determine the methane and carbon dioxide production with an open-circuit respirometry system that was equipped with respiratory chambers. The net energy (NE) and metabolizable energy (ME) requirements for maintenance and growth were calculated using the carbon and nitrogen balance method. The results revealed that the carbon (C) and nitrogen (N) excretions and energy losses at faeces and urine, as well as the output of methane and CO2, increased significantly with decreasing feed intake (P

A comparative slaughter trial was conducted to determine the net mineral requirements for maintenance and growth of Dorper crossbred female lambs raised from 20 to 35 kg of body weight (BW). Thirty-five Dorper×thin-tailed Han crossbred female lambs of (20.3±1.14) kg BW were used: 7 lambs were randomly chosen and slaughtered at the beginning of the experiment as the baseline group for measuring the initial body composition; another 7 lambs were randomly chosen and offered a pelleted mixed diet ad libitum and slaughtered at (27.0±0.73) kg BW; the remaining 21 lambs were randomly divided into 3 groups of 7 animals each and subjected to the same diet either ad libitum or at 70 or 40% of ad libitum intake. The 21 lambs were fed in 7 slaughter groups, with each group consisting of one lamb from each treatment (ad libitum, 70 or 40% of ad libitum intake). The 3 groups were slaughtered when the sheep fed ad libitum attained (33.8±0.52) kg of BW. The body composition of five minerals (Ca, P, Na, K, and Mg) was determined. The net mineral requirements for maintenance were 35.01, 25.18, 9.30, 31.35, and 2.03 mg kg−1 empty BW (EBW) for Ca, P, Na, K, and Mg, respectively, and the net growth requirement per kg of EBW gain ranged from 9.73 to 8.87 g of Ca, 5.83 to 5.27 g of P, 1.73 to 1.63 g of Na, 3.73 to 4.08 g of K, and 0.26 to 0.25 g of Mg for Dorper crossbred lambs in China, respectively. The estimates of mineral requirements with Dorper crossbred lambs in the current study were not consistent with the recommendations from previous studies.

This study aimed to investigate the effects of dietary supplementation of yeast β-glucan on the nutrient digestibility and serum profiles in pre-ruminant Holstein calves. Forty-two neonatal Holstein calves ((39.6±4.2) kg) were randomly allotted to six groups, and each was offered one of the following diets: a basal diet (control) or the basal diet supplemented with 25, 50, 75, 100 or 200 mg of yeast β-glucan kg−1 feed (dry matter basis). The basal diet consisted of a milk replacer and a starter feed. The trial lasted for 56 d. Two digestibility trials were conducted from d 14 to 20 and from d 42 to 48. Blood samples were collected on d 0, 14, 28 and 42 for serum profile analyses. On d 56, three calves from each group were slaughtered, and intestinal samples were collected to assess the villous height, crypt depth and mucosal thickness. Although feed intake was not affected by dietary treatment (P>0.05), the average daily gain (ADG) and gain-to-feed ratios were higher (P0.05). Compared with the control group, supplementation of yeast β-glucan decreased (P0.05). The supplementation of yeast β-glucan stimulated the enzymatic activity of alkaline phosphatase (ALP) (P

A comparative slaughter trial and a metabolism trial were conducted to determine the requirement of net energy (NE) and metabolizable energy (ME) by the crossbreed of German Mutton Merino×Inner Mongolia Merino for fattening from 35 to 50 kg of body weight (BW). 49 crossbred female lambs ((33.9±2.3) (SD) kg BW) of German Mutton Merino×Inner Mongolia Merino were used. 34 lambs were randomly chosen for comparative slaughter, which were offered an identical mixture diet (concentrate:roughage=55:45) at 100, 75 or 55% of ad libitum intake, whereas the remainders were used in the metabolism trial to evaluate the ME of the diet after methane production was measured by open-circuit respirometry. As feed intake decreased from 100 to 75 and 55% of ad libitum intake, the apparent digestibility of dry matter (DM) linearly increased ( P =0.010) from 60.8 to 63.6 and 66.9%, respectively, and methane production decreased from 52.1 to 44.3 and 39.9 L d −1 , respectively, but the ratio of methane energy to gross energy intake increased linearly ( P =0.010) from 8.20 to 8.96 and 10.97%, respectively. Consequently, the ME values of the diet increased from 9.35 to 9.64 and 9.85 MJ kg −1 DM, respectively. The NE requirement for maintenance (NE m ) was 255 kJ kg −1 BW 0.75 , and the ME requirement for maintenance (ME m ) was 352 kJ kg −1 BW 0.75 , with a partial energy efficiency for maintenance (k m ) of 0.72. The NE requirement for growth (NE g ) ranged from 1.26 to 4.66 MJ d −1 as average daily gains increased from 100 to 300 g d −1 , with a partial energy efficiency for growth (k g ) of 0.45. These results indicated that the NE g required by crossbred female lambs of German Mutton Merino×Inner Mongolia Merino was lower than the recommendation of the American or British nutritional system.

Two feeding patterns of the segregated weaning or grazing in the pasture are carried out worldwide in animal production. To investigate the difference of growth performance and rumen microorganism population related to methane metabolism in the two feeding patterns, three groups of lambs (70 in total) were used: Weaning at 21 days old and being subjected to high-concentration diets (3WK group with 20 lambs), weaning at 35 days old and being subjected to high-concentration diets (5WK group with 20 lambs), or grazing at pasture with the nursing mother (Grazing group with 30 lambs). The growth performance, pH value of rumen content, and the rumen microbes were investigated during weaning period and fattening period with approximately 3 months. Our results showed that lambs in 3WK and 5WK groups demonstrated a better growth performance than the lambs in Grazing group, but no significant difference was observed in the pH value between the three groups (P>0.05). The total rumen bacterial population of the Grazing lambs was significantly lower than that of 3WK lambs (P