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The objectives of this study were to estimate variance components and identify regions of the genome associated with traits related to embryo transfer in Holsteins. Reproductive technologies are used in the dairy industry to increase the reproductive rate of superior females. A drawback of these methods remains the variability of animal responses to the procedures. If some variability can be explained genetically, selection can be used to improve animal response. Data collected from a Holstein dairy farm in Florida from 2008 to 2015 included 926 superovulation records (number of structures recovered and number of good embryos), 628 in vitro fertilization records (number of oocytes collected, number of cleaved embryos, number of high-and low-quality embryos, and number of transferrable embryos), and 12,089 embryo transfer records (pregnancy success). Two methods of transformation (logarithmic and Anscombe) were applied to count variables and results were compared. Univariate animal models were fitted for each trait with the exception of pregnancy success after embryo transfer. Due to the binary nature of the latter trait, a threshold liability model was fitted that accounted for the genetic effect of both the recipient and the embryo. Both transformation methods produced similar results. Single-step genomic BLUP analyses were performed and SNP effects estimated for traits with a significant genetic component. Heritability of number of structures recovered and number of good embryos when log-transformed were 0.27 +/- 0.08 and 0.15 +/- 0.07, respectively. Heritability estimates from the in vitro fertilization data ranged from 0.01 +/- 0.08 to 0.21 +/- 0.15, but were not significantly different from zero. Recipient and embryo heritability (standard deviation) of pregnancy success after embryo transfer was 0.03 (0.01) and 0.02 (0.01), respectively. The 10-SNP window explaining the largest proportion of variance (0.37%) for total structures collected was located on chromosome 8 beginning at 55,663,248 bp. Similar regions were identified for number of good embryos, with the largest proportion of variance (0.43%) explained by a 10-SNP window on chromosome 14 beginning at 26,713,734 bp. Results indicate that there is a genetic component for some traits related to superovulation and that selection should be possible. Moreover, the genetic component for superovulation traits involves some genomic regions that are similar to those for other fertility traits currently evaluated. Agriculture and Food Research Initiative Grant from the National Institute of Food and Agriculture - 2013-68004-20365 United States Department of Agriculture (USDA) USDA Agricultural Research Service - 1265-31000-096-00 Southeast Milk Checkoff Program

The objective of this study was to investigate the effects of increasing doses of carvacrol (C) and/or thymol (T) on the performance, rumen fermentation, and blood and carcass parameters of Merino sheep. Eighty-four 12-week-old male Merino lambs were randomly assigned to 7 treatment groups. The sheep were fed with the same concentrate mixtures including a control diet, carvacrol 100 mg/kg (C 100 ), carvacrol 300 mg/kg (C 300 ), thymol 100 mg/kg (T 100 ), thymol 300 mg/kg (T 300 ), carvacrol+thymol 100 mg/kg (C 50 +T 50 ), and carvacrol+thymol 300 mg/kg (C 150 +T 150 ). The C and/or T supplementation did not affect the feed conversion. The lambs fed with C and/or T diets had higher rumen pH, NH 3 -N, and total volatile fatty acid (VFA) compared to those in the control group. However, essential oil supplementation did not change the molar concentration of VFA. The serum urea and glucose in C and/or T groups were not found significant on days 0, 35, and 70 compared to the control group. Slaughter weights and other carcass parameters were similar between the groups. The effects of C and/or T supplementation on the rumen and production parameters showed limited effects when lambs were fed with the high concentrate diets.

The objective of this study was to investigate the effect of processing type of feed on the fattening performance and carcass traits of Awassi ram lambs. A total of 26, three month old Awassi ram lambs were used and randomly allocated into three groups (group 1, fed with ground feed, n = 8; group 2, fed with pellet feed, n = 9; group 3, fed with extruded pellet feed, n = 9). The results showed that total weight gain and Average Daily Gain (ADG) of ram lambs during the study were 12.8 +/- 1.1 kg and 180.9 +/- 17.7 g for group 1, 12.8 +/- 0.9 kg and 252.1 +/- 21.5 g for group 2 and 14.6 +/- 0.6 kg and 287.8 +/- 23.4 g for group 3, respectively. The difference of ADG among groups were significant (p0.05). The results of the current study shows that feeding of Awassi ram lambs with extruded feed had positive effects on fattening performance, Feed Conversion Rate (FCR) and fattening period which are economically important for sheep farms.

We compared diurnal patterns of vaginal temperature in lactating cows under grazing conditions to evaluate genotype effects on body temperature regulation. Genotypes evaluated were Holstein, Jersey, Jersey x Holstein and Swedish Red x Holstein. The comparison of Holstein and Jersey versus Jersey x Holstein provided a test of whether heterosis effects body temperature regulation. Cows were fitted with intravaginal temperature recording devices that measured vaginal temperature every 15 min for 7 days. Vaginal temperature was affected by time of day (P < 0.0001) and genotype x time (P < 0.0001) regardless of whether days in milk and milk yield were used as covariates. Additional analyses indicated that the Swedish Red x Holstein had a different pattern of vaginal temperatures than the other three genotypes (Swedish Red x Holstein vs others x time; P < 0.0001) and that Holstein and Jersey had a different pattern than Jersey x Holstein [(Holstein + Jersey vs Jersey x Holstein) x time, P < 0.0001]. However, Holstein had a similar pattern to Jersey [(Holstein vs Jersey) x time, P > 0.10]. These genotype x time interactions reflect two effects. First, Swedish Red x Holstein had higher vaginal temperatures than the other genotypes in the late morning and afternoon but not after the evening milking. Secondly, Jersey x Holstein had lower vaginal temperatures than other genotypes in the late morning and afternoon and again in the late night and early morning. Results point out that there are effects of specific genotypes and evidence for heterosis on regulation of body temperature of lactating cows maintained under grazing conditions and suggest that genetic improvement for thermotolerance through breed choice or genetic selection is possible.

Animals inheriting the slick hair gene have a short, sleek, and sometimes glossy coat. The objective of the present study was to determine whether slick-haired Holstein cows regulate body temperature more effectively than wild-type Holstein cows when exposed to an acute increase in heat stress. Lactating slick cows (n = 10) and wild-type cows (n = 10) were placed for 10 h in an indoor environment with a solid roof, fans, and evaporative cooling or in an outdoor environment with shade cloth and no fans or evaporative cooling. Cows were exposed to both environments in a single reversal design. Vaginal temperature, respiration rate, surface temperature, and sweating rate were measured at 1200, 1500, 1800, and 2100 h (replicate 1) or 1200 and 1500 h (replicate 2), and blood samples were collected for plasma cortisol concentration. Cows in the outdoor environment had higher vaginal and surface temperatures, respiration rates, and sweating rates than cows in the indoor environment. In both environments, slick-haired cows had lower vaginal temperatures (indoor: 39.0 vs. 39.4 degrees C; outdoor 39.6 vs. 40.2 degrees C; SEM = 0.07) and respiration rate (indoor: 67 vs. 79 breaths/min; outdoor 97 vs. 107 breaths/min; SEM = 5.5) than wild-type cows and greater sweating rates in unclipped areas of skin (indoor: 57 vs. 43 g.h(-1)/m(2); outdoor 82 vs. 61 g.h(-1)/m(2); SEM = 8). Clipping the hair at the site of sweating measurement eliminated the difference between slick-haired and wild-type cows. Results indicate that slick-haired Holstein cows can regulate body temperature more effectively than wild-type cows during heat stress. One reason slick-haired animals are better able to regulate body temperature is increased sweating rate. Initiative for Future Agricultural and Food Systems Program (2001-52101-11318 )

Dairy cows with increased rectal temperature experience lower milk yield and fertility. Rectal temperature during heat stress is heritable, so genetic selection for body temperature regulation could reduce effects of heat stress on production. One aim of the study was to validate the relationship between genotype and heat tolerance for single nucleotide polymorphisms (SNPs) previously associated with resistance to heat stress. A second aim was to identify new SNPs associated with heat stress resistance. Thermotolerance was assessed in lactating Holsteins during the summer by measuring rectal temperature (a direct measurement of body temperature regulation; n = 435), respiration rate (an indirect measurement of body temperature regulation, n = 450) and sweating rate (the major evaporative cooling mechanism in cattle, n = 455). The association between genotype and thermotolerance was evaluated for 19 SNPs previously associated with rectal temperature from a genomewide analysis study (GWAS), four SNPs previously associated with change in milk yield during heat stress from GWAS, 2 candidate gene SNPs previously associated with rectal temperature and respiration rate during heat stress (ATPA1A and HSP70A) and 66 SNPs in genes previously shown to be associated with reproduction, production or health traits in Holsteins. For SNPs previously associated with heat tolerance, regions of BTA4, BTA6 and BTA24 were associated with rectal temperature; regions of BTA6 and BTA24 were associated with respiration rate; and regions of BTA5, BTA26 and BTA29 were associated with sweating rate. New SNPs were identified for rectal temperature (n = 12), respiration rate (n = 8) and sweating rate (n = 3) from among those previously associated with production, reproduction or health traits. The SNP that explained the most variation were PGR and ASL for rectal temperature, ACAT2 and HSD17B7 for respiration rate, and ARL6IP1 and SERPINE2 for sweating rate. ARL6IP1 was associated with all three thermotolerance traits. In conclusion, specific genetic markers responsible for genetic variation in thermoregulation during heat stress in Holsteins were identified. These markers may prove useful in genetic selection for heat tolerance in Holstein cattle. Agriculture and Food Research Initiative from the USDA National Institute of Food and Agriculture (2010-85122-20623) Agriculture and Food Research Initiative from the USDA National Institute of Food and Agriculture (2013-68004-20365) Southeast Milk Inc.

A total of 1 200 broiler breeder eggs were collected from a commercial flock at the hen age of 37 weeks and divided into storage treatments of 5 and 15 days. Prior to storage, the eggs were further divided into pre-storage incubation (PRESI) 0 (control), 4 and 8 h treatments. Eggs in the 4 and 8 h PRESI treatment were incubated at a standard dry-bulb temperature of 38.0 degrees C. All eggs were weighed prior to and after storage, then incubated in a commercial setter and hatcher for 21 days. After the incubation, all unhatched eggs were opened to determine fertility, hatchability and embryonic death. The 4 and 8 h PRESI treatment significantly decreased hatchability results of long-term stored eggs compared to non-heated eggs. Hatchability results of eggs stored for 5 days were significantly better compared to eggs stored for 15 days. Subsequent growth performance of progeny was not significantly affected except for the main effect of egg storage on feed conversion. There were significant PRESI x egg storage interactions for apparent fertility, hatchability of total and fertile eggs and embryonic mortality. It was concluded that the PRESI treatment did not have a detrimental effect on the hatchability of broiler breeder eggs stored for 5 days and it might even increase hatchability while it had a detrimental effect on the hatchability of broiler breeder eggs stored for 15 days.

The SLICK haplotype (http://omia.angis.org.au/OMIA001372/9913/) in cattle confers animals with a short and sleek hair coat. Originally identified in Senepol cattle, the gene has been introduced into Holsteins. The objectives of the current study were to determine (1) whether lactating Holsteins with the slick hair phenotype have superior ability for thermoregulation compared with wild-type cows or relatives not inheriting the SLICK haplotype, and (2) whether seasonal depression in milk yield would be reduced in SLICK cows. In experiment 1, diurnal variation in vaginal temperature in the summer was monitored for cows housed in a freestall barn with fans and sprinklers. Vaginal temperatures were lower in slick-haired cows than in relatives and wild-type cows. In experiment 2, acute responses to heat stress were monitored after cows were moved to a dry lot in which the only heat abatement was shade cloth. The increases in rectal temperature and respiration rate caused by heat stress during the day were lower for slick cows than for relatives or wildtype cows. Moreover, sweating rate was higher for slick cows than for cows of the other 2 types. In experiment 3, effects of season of calving (summer vs. winter) on milk yield and composition were determined. Compared with milk yield of cows calving in winter, milk yield during the first 90 d in milk was lower for cows calving in the slimmer. However, this reduction was less pronounced for slick cows than for wild-type cows. In conclusion, Holsteins with slick hair have superior thermoregulatory ability compared with non-slick animals and experience a less drastic depression in milk yield during the summer. USDA National Institute of Food and Agriculture (Washington, DC) (2010-85122-20623) (2013-68004-20365) Southeast Milk Inc. Milk Check-off Program

Heat stress has an important effect on the welfare of livestock and causes significant changes in biological functions. This study was carried out to investigate the behavioral differences of Brown Swiss (BS) and Holstein (H) feedlot cattle reared in a hot environment. All of the cattle were housed in a semi-open feedlot barn. The individual behavioral response variables measured were feeding, drinking, rumination, standing, resting, locomotor activity and elimination (urinating and defecating). For each animal, behavioral observations were recorded at 10 mm intervals for 1 h starting at 06:00, 10:00, 13:00, 16:00, 20:00 and 23:00 h. The effect of breed, time of the day and hour of observation and the interactions of these factors were included in the model. The data were analyzed using the PROC GLM procedure in SAS. There were significant interactions between breed and time of observation for rumination (p < 0.001), standing (p < 0.001), resting (p < 0.01), time of feeding and locomotor activities (p < 0.05). Overall, feeding behavior was greater for BS cattle (p < 0.05). Resting behavior was greater for H (p < 0.01) and was primarily observed late at night (23:00 h). The observed effects of breed on behavior within the observation times from 06:00 to 23:00 h were significant (p < 0.05 and p < 0.001) except for the hour of observation beginning at 10:00 h (p > 0.05). BS cattle exhibited more frequent standing behavior at 13:00 h, whereas H cattle exhibited more frequent standing behavior at 16:00 h (p < 0.01). The welfare of male H feedlot cattle was concluded to be more affected than that of male BS feedlot cattle when the ambient temperature was high.

The present study was carried out to determine the sex of the fertilized white layer eggs with using morphological measurements. A total of 300 Super Nick White Layer (54 wks of age) eggs were incubated and sexed in the end of incubation period. Before incubation egg length, width and weight were measured. The egg volume and shape index were estimated with using these measurements for each egg. The effect of egg weight and replicate number was not significant on the sex of the hatching chick (p > 0.05). The effects of egg shape index (p = 0.001), egg length (p = 0.0018), egg width (p < 0.01) and volume (p = 0.004) of the egg had significant effect on the sex of hatching chick. According to the results of the current study, morphological measurements of the pre-incubated egg might be an indicator of sex of the hatching chick. The shape index and egg volume were more informative for the likelihood of the sex of hatching chick. According to the positive results of the current study, it is possible to incubate more female chicks with using the morphological measurements of egg. This may increase the incubation capacity and decrease the number male chicks that are killed at layer hatcheries.

Genetic selection for body temperature during heat stress might be a useful approach to reduce the magnitude of heat stress effects on production and reproduction. Objectives of the study were to estimate the genetic parameters of rectal temperature (PT) in dairy cows in freestall barns under heat stress conditions and to determine the genetic and phenotypic correlations of rectal temperature with other traits. Afternoon PT were measured in a total of 1,695 lactating Holstein cows sired by 509 bulls during the summer in North Florida.. Genetic parameters were estimated with Gibbs sampling, and best linear unbiased predictions of breeding values were predicted using an animal model. The heritability of RT was estimated to be 0.17 +/- 0.13. Predicted transmitting abilities for rectal temperature changed 0.0068 +/- 0.0020 degrees C/yr from (birth year) 2002 to 2008. Approximate genetic correlations between RT and 305-d milk, fat, and protein yields, productive life, and net merit were significant and positive; whereas approximate genetic correlations between TIT and somatic cell count score and daughter pregnancy rate were significant and negative. Rectal temperature during heat stress has moderate heritability, but genetic correlations with economically important traits mean that selection for RT could lead to lower productivity unless methods are used to identify genes affecting RT that do not adversely affect other traits of economic importance. National Research Initiative Competitive from the USDA National Institute of Food and Agriculture - 2010-85122-20623

Heat stress has important effects on the welfare of livestock. The effects of heat stress in cattle include changes in biological functions and behaviors. The aim of this study was to investigate the behavioral differences between light and heavy feedlot cattle reared in a hot environment. Sixteen male Holstein feedlot cattle were allocated to light (353.8 +/- 15.5 kg, n = 8) and heavy (737.1 +/- 15.8 kg, n = 8) groups according to their live weight and were kept in a semi-open feedlot barn. The individual behavioral response variables measured were standing, lying, feeding, drinking, ruminating, locomotor activity and elimination (urinating and defecating). The effects of group, day, observation time, replicate and all interactions were included in an explanatory statistical (GLM) model. The data were analyzed using the PROC GLM procedure of SAS. Overall, the heavy cattle spent more time standing (P < 0.001), lying (P < 0.001), and eliminating (P < 0.05) compared to the light group. In contrast, the light group spent more time eating, drinking and ruminating (P < 0.001). Locomotor activity did not differ significantly between groups (P > 0.05). During the day, heavy cattle spent more time standing (at 1600 hours) and less time eating in comparison with the light cattle (P < 0.001) (at 1300 and 1600 hours). Light and heavy feedlot cattle behaved differently in a hot environment. The findings of the study indicate that the welfare of the heavy Holstein feedlot cattle was impacted negatively when the ambient temperature was high (at 1300 hours).

The objectives of this experiment were to evaluate the accuracy of ultrasonography to measure subcutaneous fat thickness (SFT) and LM traits (area, depth, and width) in live Awassi lambs of different sexes, predict actual SFT and LM traits without damage to the carcass, and improve carcass classification. Data were obtained from ultrasound scans of 20 female and 10 male lambs. Female lambs were randomly divided into light (FL; n = 10) and heavy (FH; n = 10) finishing groups. Slaughter weights of lambs in FL were 30 kg and for FH and male groups were 40 kg. Subcutaneous fat thickness and LM traits, cross-sectional area between the 12th and 13th rib were measured using real-time ultrasound in vivo and on the carcass after slaughter. All ultrasound and carcass measurements were different (P > 0.05) except carcass yield and carcass LM width in female lambs (FL and FH). Between different sex groups, all ultrasound and carcass measurements were the same except ultrasound SFT (USFT; P = 0.04) and carcass SFT (CSFT; P = 0.03). Significant correlation coefficients were between USFT and CSFT (0.93, P < 0.01; 0.76, P = 0.02), ultrasound LM depth (ULMD) and carcass LM depth (CLMD; 0.64, P = 0.05; 0.77, P < 0.01), and ultrasound LM area (ULMA) and carcass LM area (CLMA; 0.88, 0.84; P < 0.01) for female lambs in FL and FH groups. Also, similar correlations were determined significantly between USFT and CSFT (0.84, P < 0.01; 0.76, P = 0.02), ULMD and CLMD (0.69, P = 0.03; 0.77, P < 0.01), and ULMA and CLMA (0.88, 0.84; P < 0.01) for male lambs in male and FH groups. The introduction of USFT and ULMA as independent variables in addition to BW in the multiple regression equations further improved the variations for CSFT (88, 75, and 81%) and CLMA (78, 90, and 80%) for lambs in FL, FH, and male groups, respectively, whereas no improvement was observed for cold carcass weight with the exception of the FH group and carcass yield. These results indicate that in vivo USFT and ULMA in association with BW could be used to estimate CSFT, CLMA, and cold carcass weight ultrasound findings about LM, and SFT can be included to the selection programs for different BW and sex of Awassi lambs.

This experiment was conducted to investigate the effect of cafeteria (CF) and conventional (CN) feeding systems on feed intake, feed preferences with respect to voluntary feed source intake, feed conversion rate (FCR) and fattening performance of native Awassi lambs. Sixteen, 3 month old male lambs were used and kept individually for 70 days. Lambs in CF (n = 8) were offered to consume the main ingredients of barley, soybean meal (SBM), sunflower seed meal (SFM) and alfalfa straw, separately, while lambs in CN (n = 8) were fed with a concentrate feed containing 11.34 MJ/kg ME, 17.53% crude protein with the mixture of the same feed sources and alfalfa straw. The initial and final live weights of lambs were similar among groups (P > 0.05). Daily voluntary intake of ash, fat and neutral detergent fiber (NDF) consumptions among groups were quite different during the experiment (P < 0.001). Neither biweekly nor total results of voluntary protein intake between groups were not found statistically significant (P > 0.05). From beginning to the end of the study, the proportional barley intake increased 34 to 43% but reduced for SBM intake from 37 to 23% for the lambs in CF. On the other hand, the SFM intake of lambs did not changed significantly during the experiment and ranged between 2-5%. Lambs in CF did not consume SFM to meet their protein requirement and had 12.5% better total FCR result than the lambs in CN (6.86 and 7.84, respectively) (P > 0.05). The difference of average DWG, total live weight gain, final live weight of lambs in groups were similar (P > 0.05). In conclusion, Awassi lambs in CF can select a diet matching their nutritional requirements from a group of feed sources in response to their growth period when compared to CN system and better FCR result might help to decrease the feed expenses for fattening of native Awassi lambs.

Several temperature-humidity indexes (THI) have been used to estimate the degree of thermal stress experienced by dairy cows. The present objectives were to develop equations using meteorological variables that predicted rectal temperature of lactating cows in a subtropical environment and compare the goodness of fit of these equations to those using 8 different THI. Rectal temperature was measured between 1500 and 1700 h in 1,280 lactating Holstein cows in north central Florida between August and December. Meteorological data recorded in the barn where cows were located included dry bulb temperature (T(db)), relative humidity (RH), dew point temperature, and wind speed. Wet bulb temperature was calculated. In the first series of analyses, regression analysis was used to model rectal temperature using the meteorological variables as well as THI. The r(2) using T(db) (0.41) was slightly less than for models using all but one THI (r(2) between 0.42 and 0.43). The r(2) for equations using T(db) could be improved by adding RH (r(2) = 0.43) or RH and RH(2) (r(2) = 0.44) to the model. In the second analysis, regression analysis was performed using forward selection, backward elimination, and stepwise selection procedures with the meteorological variables. All models gave a similar goodness of fit (r(2) = 0.44). An analysis of variance with rectal temperature as a class variable was performed to determine the least squares means of meteorological measurements associated with hyperthermia. A T(db) of 29.7 degrees C was associated with rectal temperature of 39 degrees C, and a T(db) of 31.4 degrees C was associated with rectal temperature of 39.5 degrees C. In conclusion, T(db) is nearly as good a predictor of rectal temperatures of lactating Holsteins in a subtropical environment as THI. Estimates of values of meteorological variables associated with specific rectal temperatures should prove valuable in relating environmental conditions to the magnitude of hyperthermia experienced by heat-stressed cows.

The accuracy of ultrasonography to measure fat thickness (FT) and longissimus dorsi muscle (LM) traits (area, depth and width) in live Awassi male lambs and predict carcass FT and LM traits was studied. Twenty six Awassi male lambs were randomly divided into light (L) (n = 13) and heavy (H) (n = 13) finishing lambs. Slaughter weight of lambs in L and H groups were 40 and 45 kg, respectively. FT and LM traits, cross-sectional area between the 12th and 13th rib were measured using real-time ultrasound in vivo and on the carcass after slaughter. All ultrasound and carcass measurements were the same except live weight (LW) (P 0.05) and 0.89, 0.87 (P< 0.001), respectively, for lambs in L and H groups. The introduction of ultrasound FT and ultrasound LM area as independent variables in addition to LW in the multiple regression equations further improved the variations for carcass FT (84%, 71%), carcass LM area (79%, 79%). CCW (72%, 65%) for lambs in light and heavy groups whereas no improvement was observed for carcass yield. These results indicate that in vivo ultrasound FT and measurement of the LM area in association with LW could be used to estimate carcass FT, carcass LM area and CCW in different LW Awassi lambs.

This study was made to compare physical chick quality indicators such as chick length and feather colour and their effects on the uniformity and subsequent growth performance in broiler. For this reason; 600 day old male chicks were used. Chicks were classified into two groups on the basis of their feather colour: deep and light yellow. Then, chicks in each group were further divided into three groups as small, middle and large according to their body length. The length of the middle group animals was varied between 18.0–18.3 cm, while that of the largest group was greater than 18.3 cm and the small group was lesser than 18.0 cm. A positive correlation between chick length and chick weight was observed in all groups at the 0 day of age. Body length uniformity in day old chick was more important than body weight uniformity. Longer chicks exhibited better growth potential throughout the experiment. The feeding efficiency and survival rate of longer chicks were numerically greater compared to smaller chicks. There were no significant differences for subsequent growth parameters in feather colour groups. Consequently; length of day old chick can be used as important criteria for selection of higher quality chicks having better growth performance.