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Ovsynch is a widely accepted estrus synchronization protocol for improving the reproductive performance of water buffaloes who manifest low reproductive efficiency. Recently, some modified protocols based on Ovsynch such as 2 injections of prostaglandin 14 days apart following the Ovsynch are also introduced to enhance the reproductive potential of this species. In the present study, a meta-analytical assessment was performed with the objective to evaluate the reproductive performance of water buffaloes synchronized with Ovsynch or modified Ovsynch programs. Meta-analysis of the fixed or random effects model was determined by the heterogeneity among the studies. Reproductive outcome of interest was pregnancy per artificial insemination (P/AI) measured on day 25 (25–100). A total of 32 articles including 4003 buffaloes using either Ovsynch or modified Ovsynch protocol were reviewed. In the random effects model for buffaloes, the overall proportion of P/AI was 42.55% [95% confidence interval (CI): 37.48–47.70; n = 3,089] and 46.44% (95% CI: 39.63–53.31; n = 914) on day 25 after AI for Ovsynch and modified Ovsynch, respectively. Results for P/AI were then categorized by ovarian activity, where P/AI was available for 3575 cyclic buffaloes and 320 non-cyclic buffaloes. For cyclic buffaloes, the overall proportion of P/AI was 47.54% (95% CI: 42.72–52.38; n = 2911) and 57.97% (95% CI: 54.12–61.77; n = 664) on day 25 after AI for Ovsynch and modified Ovsynch, respectively. In the fixed effects model for non-cyclic buffaloes, the overall proportion of P/AI was 19.68% (95% CI: 13.48–26.58; n = 167) and 33.01% (95% CI: 25.50–40.94; n = 153) on day 25 after AI for Ovsynch and modified Ovsynch, respectively. In conclusion, a benefit for P/AI is detected in buffaloes with the modified Ovsynch protocol. Besides, whichever estrus synchronization protocols (Ovsynch or modified Ovsynch), cyclic buffaloes have higher P/AI compared with non-cyclic buffaloes.

The aim of this study was to evaluate the effect of different feed restriction regimens on performance, behavioral patterns, blood cortisol, and carcass parameters in Sasso broilers. Sixty healthy 1-day-old unsexed Sasso chicks were randomly assigned to three groups (20 chicks per group) and each group was divided into 4 replicates with 5 chicks each based on feed restriction program during the rearing period (60 days). The first group (G1) is control in which birds were fed ad libitum had free access to feed (no restriction). The second group (G2) was subjected to temporary feed restriction at the first 2 weeks as birds had access to feed for 12 h only after that they had free access to feed until the end of the experimental period. The third one (G3) was subjected to continuous feed restriction as birds had free access to feed for 12 h only throughout the rearing periods. During the study period, growth performance and behavioral patterns were estimated. At the end of the study, blood samples for cortisol testing were taken. Three birds from each group were slaughtered at the end of the study to see how the feed restriction affected carcass parameters. Feed restriction had a substantial impact (P ≤ 0.05) on final body weight and carcass parameters. Feed restriction elevated blood cortisol significantly (P = 0.004). Feed restriction showed a significant impact on some behaviors as feeding, stretching, preening, and aggression. Overall, different feed restriction programs had a wide effect on growth performance, behaviors, cortisol concentration, and carcass parameters of Sasso broilers.

Simple Summary Some studies have confirmed the variation in milk profiles when dairy cows show estrus. However, only a few milk components, such as fat, protein, and lactose, have been investigated so far, and thus any changes in the many other parts of milk’s composition due to estrus are unknown. Milk mid-infrared (MIR) spectra consist of wavenumbers, which provide insight into the chemical composition of milk. The MIR spectrum reflects the global composition of milk, but this information is currently underused. In this study, we considered MIR wavenumbers as traits, and directly studied the spectral information as a way to study the estrus of dairy cows linked to milk composition. This research provides a deeper understanding of the milk MIR spectrum and may lead to new approaches for estrus detection in dairy cows from routine milk analysis, thereby guiding an opportune insemination time. Abstract Milk produced by dairy cows is a complex combination of many components. However, at present, changes in only a few milk components (e.g., fat, protein, and lactose) during the estrus cycle in dairy cows have been documented. Mid-infrared (MIR) spectroscopy is a worldwide method routinely used for milk analysis, as MIR spectra reflect the global composition of milk. Therefore, this study aimed to investigate the changes in milk MIR spectra and milk production traits (fat, protein, lactose, urea, total solids (TS), and solid not fat (SnF)) due to estrus. Cows that were successfully inseminated, leading to conception, were included. Cows confirmed to be pregnant were considered to be in estrus at the day of insemination (day 0). A general linear mixed model, which included the random effect of cows, the fixed classification effects of parity number, days in relation to estrus, as well as the interaction between parity number and days in relation to estrus, was applied to investigate the changes in milk production traits and 1060 milk infrared wavenumbers, ranging from 925 to 5011 cm−1, of 371 records from 162 Holstein cows on the days before (day −3, day −2, and day −1) and on the day of estrus (day 0). The days in relation to estrus had a significant effect on fat, protein, urea, TS, and SnF, whose contents increased from day −3 to day 0. Lactose did not seem to be significantly influenced by the occurrence of estrus. The days in relation to estrus had significant effects on the majority of the wavenumbers. Besides, we found that some of the wavenumbers in the water absorption regions were significantly changed on the days before and on the day of estrus. This suggests that these wavenumbers may contain useful information. In conclusion, the changes in the milk composition due to estrus can be observed through the analysis of the milk MIR spectrum. Further analyses are warranted to more deeply explore the potential use of milk MIR spectra in the detection of estrus.

The current study was conducted to evaluate the effect of parity and days in milk on milk yield and milk production traits and their correlation with β-hydroxybutyrate (BHB) concentrations in milk of Chinese tropic Holstein dairy cows which are adapted to a humid subtropical climate in central China. About 3055 milking records of Holstein cows were obtained from three farms in the hot region in the center of China. The records were classified according to parity to 4 categories: first parity, second parity, third parity, and greater than third parity. According to days in milk, there were 4 groups, first group from (1-100 days), second group from (101-200 days), third group from (201-305 days), and fourth group (>305 days). Milk samples collected between April and November 2019 from the three farms were routinely checked for milk components including BHB using mid-infrared spectroscopy a MilkoScan FT+ (Foss, Hillerod, Denmark). Data were analyzed by multivariate analysis of variance (generalized linear model, GLM). Pearson's correlation coefficients were used to measure the correlation between SCC and BHB with milk yield and milk production traits. Results showed the significant effect of parity and days in milk on milk yield and milk production traits. There was a negative effect of parity and days in milk on milk quality, with increasing parity and days in milk being associated with higher somatic cell count (SCC) (P

This study aimed to investigate the effects of polymorphisms in growth hormone 1 (GH1) gene on the growth traits in Chinese indigenous yak. Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) approach, one novel single-nucleotide polymorphism (SNP), termed as g.1721G>A, was identified in the exon 4 of GH1 gene in 423 individuals of yak population. Based on the chi-square (χ2) test, the frequencies of g.1721G>A alleles agreed with Hardy-Weinberg equilibrium (HWE) (P < 0.05). A significant association was observed between this SNP and several growth traits (P < 0.01 or P < 0.05), in which the genotype GG exhibited the best values. The present study suggested that the identified SNP was a useful genetic marker for the improvement of growth traits in Chinese indigenous yak.

Milk composition always serves as an indicator for the cow&rsquo, s health status and body condition. Some non-genetic factors such as parity, days in milk (DIM), and calving season, which obviously affect milk performance, therefore, need to be considered in dairy farm management. However, only a few milk compositions are used in the current animal selection programs. The mid-infrared (MIR) spectroscopy can reflect the global composition of milk, but this information is currently underused. The objectives of this study were to detect the effect of some non-genetic factors on milk production traits as well as 1060 individual spectral points covering from 925.92 cm&minus, 1 to 5011.54 cm&minus, 1, estimate heritabilities of milk production traits and MIR spectral wavenumbers, and explore the genetic correlations between milk production traits and 1060 individual spectral points in a Chinese Holstein population. The mixed models procedure of SAS software was used to test the non-genetic factors. Single-trait animal models were used to estimate heritabilities and bivariate animal models were used to estimate genetic correlations using the package of ASReml in R software. The results showed that herd, parity, calving season, and lactation stage had significant effects on the percentages of protein and lactose, whereas herd and lactation stage had significant effects on fat percentage. Moreover, the herd showed a significant effect on all of the 1060 individual wavenumbers, whereas lactation stage, parity, and calving season had significant effect on most of the wavenumbers of the lactose-region (925 cm&minus, 1 to 1200 cm&minus, 1), protein-region (1240 cm&minus, 1 to 1600 cm&minus, 1), and fat-regions (1680 cm&minus, 1 to 1770 cm&minus, 1 and 2800 cm&minus, 1 to 3015 cm&minus, 1). The estimated heritabilities for protein percentage (PP), fat percentage (FP), and lactose percentage (LP) were 0.08, 0.05, and 0.09, respectively. Further, the milk spectrum was heritable but low for most individual points. Heritabilities of 1060 individual spectral points were 0.04 on average, ranging from 0 to 0.11. In particular, heritabilities for wavenumbers of spectral regions related to water absorption were very low and even null, and heritabilities for wavenumbers of specific MIR regions associated with fat-I, fat-II, protein, and lactose were 0.04, 0.06, 0.05, and 0.06 on average, respectively. The genetic correlations between PP and FP, PP and LP, FP, and LP were 0.78, &minus, 0.29, and &minus, 0.14, respectively. In addition, PP, FP, and LP shared the similar patterns of genetic correlations with the spectral wavenumbers. The genetic correlations between milk production traits and spectral regions related to important milk components varied from weak to very strong (0.01 to 0.94, and &minus, 0.01 to &minus, 0.96). The current study could be used as a management tool for dairy farms and also provides a further understanding of the genetic background of milk MIR spectra.