Livestock Science最新文献

In order to explore a less stressful and hormone-independent insemination method in rabbits, we aimed to evaluate the influence of a new insemination cannula on reproductive performance. Two assays were conducted. In the first, 136 nulliparous and multiparous females were treated with 12.5 IU of eCG to improve their receptivity and divided into four stimulation groups (aGnRHControl, Extender, Seminal and Sperm) to test ovulation frequency and rate. The control group received 1 µg of buserelin acetate intramuscularly to induce ovulation. The other groups used a 3D printed cannula to introduce 0.5 ml of extender, undiluted seminal plasma or resuspended sperm into the vagina. After six days, laparoscopy was performed to assess ovulation frequency and rate. Results showed that nulliparous does exhibited higher ovulation frequencies compared to multiparous does, regardless of the stimulation group.

In the second assay, reproductive performance (delivery rate and litter size at birth) of 109 females treated with 12.5 IU of eCG to improve their receptivity was studied after insemination with a seminal dose using the 3D printed cannula. Forty-nine of them were induced to ovulate with buserelin acetate as a control. The results confirmed previous findings, as cannula stimulation allowed better delivery rates in receptive nulliparous than multiparous does. Differential response to multiparous does to the physical stimulus of the cannula could be supported by the histological changes and loss of contractile response that occur after multiple births. Litter sizes at birth were similar between experimental groups.

In conclusion, the 3D designed cannula showed promising results in nulliparous does in ovulating frequency, and further refinement is needed to enhance its effectiveness, particularly in multiparous rabbits.

Dulcitol (DUL) has multiple biological functions such as anti-inflammatory, antioxidant, and anti-cancer. However, little is known about the DUL used in swine diets. This experiment investigated the effects of DUL on the growth performance, apparent digestibility of nutrient, blood profiles, and fecal microbiota of growing-finishing pigs. A total of 144 barrows (initial body weight (BW) of 30.1 ± 0.7 kg) were blocked based on BW and assigned to 4 dietary treatments in a 72-d trial, each treatment had 6 replicate pens and 6 pigs per pen. Dietary treatments included a control (CON) diet and 3 DUL diets with DUL supplementation at the concentration of 100 (DUL1), 500 (DUL2), and 1,000 (DUL3) mg/kg in the basal diet, respectively. Results showed that DUL supplementation increased the final BW, average daily gain, and average daily feed intake of pigs (p < 0.05). Additionally, DUL2 decreased the feed-to-gain ratio of the pigs and increased the apparent digestibility of gross energy, dry matter, crude protein, ash, and calcium compared to CON group (p < 0.05). The contents of IgG and IgM in serum increased linearly with an increased inclusion level of DUL, whereas the serum IL-1β and TNF-α contents were linearly decreased with the increased DUL levels (p < 0.05). Similarly, DUL addition linearly increased the activity of SOD, GSH-px, and CAT, but decreased the MDA contents in serum (p < 0.05). Microbial analysis showed that the DUL supplementation had no effects on the diversity of fecal microbiota. While LEfSe analysis showed that Rikenellaceae_RC9_gut_group was enriched in DUL1 group, while the Enterobacterales were enriched in DUL3 group. Spearman correlation analysis identified a correlation between the abundance of Lactobacillus and Prevotellaceae_NK3B31_group and the functions of antioxidants and immune (p < 0.05). Collectively, current study demonstrated that 500 mg/kg DUL supplementation could increase growth performance and nutrients digestibility, as well as promote serum immune and antioxidant indices of growing-finishing pigs.

Goat farming constitutes a significant source of income for farmers in northern Peru. There is currently an absence of information about the genetics of Peruvian Creole goats that would enable us to understand their origins and genetic spread. The objective of this study was to estimate the genetic diversity of Creole goats from northern Peru using SNP markers. This study involved the collection of 192 male Creole goats from three key goat production geographical departments in northern Peru. These goat samples were genotyped using the GGPGoat70k SNP panel. To explore the genetic influence of other breeds on Peruvian Creole goats, our dataset was combined with previously published SNP genotypes. External data set includes multiple breeds genotypes sampled from Argentina, Brazil, Spain, and Alpine breed from Italy, France, and Switzerland. After quality control 52,832 autosomal SNPs were used to assess genetic diversity in the Peruvian goats. For the population structure analysis of the merged data 20,513 common SNPs were used. Estimations for expected heterozygosity (H_e), observed heterozygosity (H_o), and inbreeding coefficient (F_IS) were computed for the Peruvian groups. AMOVA, principal component analysis and ADMIXTURE were conducted to evaluate the population structure in the two data sets, Peru and merged. The results revealed a considerable genetic diversity, with H_o values ranging from 0.40 to 0.41 for the Peruvian sampling groups, and inbreeding coefficient was notably low for Peruvian goat. The population structure analysis demonstrated a distinction (p < 0.05) from other breeds. These findings suggest a level of genetic differentiation of the Peruvian goat population among other breeds, although further research is needed considering samples from other Peruvian areas. We expect this study will contribute to define genetic management strategies to prevent the loss of genetic diversity in Peruvian goat populations and for upcoming advancements in this field.

Reproduction is crucial in the efficiency of grazing-based beef production systems. There are different ways to improve reproductive indices in cattle, such as through herd management, nutrition and/or genetics. It was shown that different levels of herbage allowance and the use of crossbred cows could improve the follicular and uterine characteristics that translate into higher cow fertility. Our study aimed to evaluate the follicle size, oocyte quality, and changes in follicular fluid composition and uterine gene expression in crossbred and purebred cycling beef cows grazing native pastures at two different levels of herbage allowance for three years. The experimental design was a complete randomized block with two replications. We allocated a total of 32 multiparous cows, with eight cows per block in a two-by-two factorial arrangement of herbage allowance (HA: High (HI) and Low (LO)) and cow genotype (CG: Purebred (PU) and Crossbred (CR)). Cows with at least two previous ovulations were slaughtered at 190 ± 15 days postpartum and uterine tissue and ovaries of the cycling cows were collected. We obtained that the preovulatory follicle size, progesterone, and insulin-like growth factor 1 (IGF1) were greater in cows with HI than with LO long-term herbage allowance. Furthermore, the non-esterified fatty acids (NEFA) concentration was lower in crossbred cows. It suggests a lower mobilization of energy reserves in crossbred than in purebred cows. For the gene expression in uterine tissues, we only observed a greater expression of IGFBP2 and IGFBP4 mRNA in cows under LO HA. These findings reveal an effect of the herbage allowance and cow genotype in follicular and uterine parameters that can be translated into better cow fertility.

Mesenteric torsion (MT) is a condition characterized by the twisting of intestinal loops, leading to a disruption in blood flow and abdominal distension. Several factors can predispose animals to this condition, which primarily affects healthy, fast-growing pigs and often results in fatal outcomes. Given the absence of studies on the genetic factors associated with this condition, our research aimed to estimate the heritability coefficient for MT and explore the genetic correlations between MT and performance traits in pigs. Our dataset comprised of 43,384 records of pigs from a maternal line from a nucleus farm. These pigs were born between 2010 and 2022 and had recorded information regarding MT status (0 for healthy and 1 for affected animals), weaning weight (WW), as well as pedigree, genotypes, and genomic estimated breeding values (GEBVs) for the following traits: MT status, days to reach 110 kg (D110), feed conversion adjusted to 110 kg (FC110), and backfat thickness adjusted to 110 kg (BT110). In our statistical model, the effects of contemporary group (CG: sex, year, and week of weaning) and the linear covariate WW were considered fixed effects, while the direct additive genetic effect was accounted as random. On average, pigs affected by MT had an age of 104.35 ± 37.75 days, and the condition had an overall herd frequency of 2.46 %. Mesenteric torsion occurred more frequently in female pigs raised in collective pens compared to non-castrated males raised in individual pens. Heritability estimates for MT, using both pedigree (0.13 ± 0.02) and genomic (0.12 ± 0.02) data, were of low magnitude. This suggests that while there is genetic variability associated with MT, a significant portion of this variation is due to environmental variance. The correlation between MT and BT110 GEBVs was of low magnitude (0.05). In contrast, the correlations between GEBVs for MT and both D110 and FC110 were moderate in magnitude (0.22 for both traits). This implies that pigs taking longer to reach 110 kg and those with poorer feed conversion are more likely to develop MT. There is genetic variability for mesenteric torsion in pigs. Selection aimed at improving feed conversion and reducing the age at which pigs reach 110 kg could lead to a decrease in the occurrence of MT within pig populations.

The whole-farm model, HolosNorSheep, was developed to estimate net greenhouse gas emissions from dual purpose sheep production in Norway. The model adopted a cradle-to-farm gate system boundary and is based on the International Panel on Climate Change methodology and includes direct emissions from enteric and manure methane (CH₄; GWP₁₀₀=27), direct and indirect nitrous oxide (N₂O; GWP₁₀₀=273) from manure and soils, direct carbon dioxide (CO₂) emissions from energy use and indirect CO₂ emissions from the production of input factors. Soil carbon balance is calculated using the ICBM-model. Emission intensities (CO₂-eq/kg product) for sheep carcass and greasy wool, was estimated for five geographical regions of Norway (East, West, South, Mid and North). The geographical regions varied considerably in climate, feed resources, days on pasture and herd/farm management. Estimated emission intensities per kg carcass and greasy wool varied from 23.5 to 19.9 (Mid region) to 26.8 and 22.8 kg CO₂-eq (North region) respectively. The difference between the Mid and North region was mainly due to higher CO₂ and N₂O emissions from use of fuel and N-fertilizer in the North, where a short growth season, and thus reduced grass yields, are compensated by using greater land area. Based on the distribution of sheep in the regions, and the emission intensities in each region, weighted average emission intensities per kg carcass and greasy wool were estimated as 25.1 and 23.3 kg CO₂-eq, respectively. Five alternative methods for the allocation of the co-products were compared with the amounts allocated to greasy wool ranging from 0 % when using no allocation (i.e., all emissions allocated to the sheep carcass), 11 % for economic allocation, 12 % for mass allocation, 19 % for biophysical allocation based on energy requirement up to 31 % for allocation based on protein mass. The emission intensity for wool was highly sensitive to the allocation method used (range from 0 to 61 kg CO₂-eq per kg greasy wool), while the effect on sheep carcass was lower (range 19 to 28 kg CO₂-eq per kg carcass). For production systems where meat is the main product, as in Norway, allocation should be based on biophysical allocation based on energy requirement.