The purpose of this study was to investigate the relationship between conception rate (CR) and climate variables. Data consisted of 24,380 inseminations of Holstein dairy herd in Hidalgo, Mexico. Weather records, including daily temperature (T), relative humidity (RH), rainfall, wind speed, and solar radiation, were obtained from a nearby weather station. Means for each climatic variable from 2 days before artificial insemination (AI) to the AI day were calculated for each conception date represented in the study. A significant negative correlation was observed between the CR and mean and minimum T, mean and minimum RH, mean and minimum temperature-humidity index (THI), and rainfall. The overall mean CR was 34.3%. The CR in lactating dairy cows followed a seasonal pattern, lower CRs were observed in summer months than during winter (32.1% vs. 36.9%; P<0.01). The variables that had the greatest influence on CR were minimum and maximum T, minimum RH, minimum THI, wind speed, and rainfall.
The objective of this study was to evaluate the effects of the CSN1S1 locus polymorphism on 305-d records of milk, fat, protein, lactose and total solids yields, fat, protein, lactose and total solids contents in Mexican dairy goats. A total of 514 lactation records belonging to Alpine (n=60), Saanen (n=105) and Toggenburg (n=74) goats, born from 2003 to 2006 in three herds were used. Discrimination between alleles E, F, N, A* (CSN1S1 A, G, H, I, O1 and O2) and B* (CSN1S1 B1, B2, B3, B4, C and L) were made by amplification of fragments of the gene CSN1S1 and digestion with the restriction endonuclease XmnI. In order to estimate additive and dominance effects, data sets including (1) all genotypes, and (2) only homozygote genotypes, were analysed using linear mixed models. The allele A*, had significant additive effects for protein content (0·21±0·07%; P=0·002) and total solids content (0·66±0·23%; P=0·005) when compared with allele F. An unfavourable additive effect of allele A* on milk yield was found in the Alpine breed (-81·4±40·2; P=0·046) when compared with allele F. Favourable dominance effects were found for some genotypes (P<0·05) for milk yield (A*N and B*N), fat yield (A*N and B*E), protein yield (A*N and B*E), lactose yield (A*N) and total solids yield (A*N). Also, unfavourable dominance effects were found (P<0·05) for protein content (A*B* and A*N) and total solids content (A*B*, A*N, and A*F). Allele A* was the only one with a positive effect for protein content. Significant allele-year interaction effects were also observed. The presence of significant dominance effects, estimated between specific pairs of alleles, challenged the purely additive nature of the genetic effect at the CSN1S1 locus. Implications from use of CSN1S1 effects in goat breeding programmes are presented.
Practical evidence suggests possible beneficial effects with the combined use of prebiotics and probiotics which can improve production parameters. The objective of the study was to investigate the addition of Saccharomyces cerevisiae (SC) as prebiotic and the combination of Lactobacillus spp. (L), Bacillus spp. (B) as probiotics on productive parameters and economic feasibility. Four hundred male pigs, hybrids of commercial genetic lines (Pietrain), were used: T1 = control group, T2 = 4 kg/tonne SC, T3 = 0.8 kg/tonne feed L and B, T4 = 4 kg/tonne SC + 0.8 kg/tonne L and B. Productive parameters were recorded in the treatment groups for four periods. Then, the viscera of five pigs per treatment were collected after slaughter to evaluate the histological changes and cytokine concentrations in the ileum. The weight gains of groups at 70-100, 100-125 and 125-150 days in the T4 group showed statistically increases (p < .05). Feed intake had a significant difference (p < .05) in T3 versus T1. The feed-conversion ratio improved for all periods in the T4 group (p < .05). The eosinophil, mononuclear infiltration and cytokines (tumor necrosis factor-α and interleukin-6) in the mucosa were lower for treatments with probiotics. In conclusion, there was an economic benefit when using both prebiotics and probiotics in the diet of pigs from weaning to finishing.
Bovine tuberculosis, caused by Mycobacterium bovis, is a disease of socio-economic and public health importance and of significance to international trade regulation. Allelic variants of several genes have been implicated in the genetic susceptibility to tuberculosis in some human populations, but little is known in cattle. We surveyed 34 European, 18 Asian, 20 Creole and 23 hybrid bovines for polymorphisms of the bovine solute carrier family 11 a1(Slc11a1) gene, formerly known as natural resistance associated macrophage protein (Nramp1), gene by typing the cattle using two microsatellite loci closely linked to this gene. The microsatellites used were 311-22, located at the 3' untranslated region (3' UTR) of the Slc11a1 gene, and ARO28 situated about 0.6 cM upstream of the same gene Based on allele size in base pairs (bp) we determined five 311-223 locus variants (221, 223, 225, 227 and 229 bp) and 12 ARO28 loci. There was marked diversity and a very high level of heterozygosity in most of the cattle surveyed except the Europeans bovines and especially Holsteins in relation to the 3' UTR microsatellite locus.
actual situación de producción de praderas básicamente con gramas nativas que durante los meses de menor frío tienen un pobre desempeño y por ende la producción de leche se deteriora lo cual promueve una gran utilización de alimentos concentrados lo que provoca un incremento en el costo de producción y una menor utilidad para estos. Para dicho propósito se realizó un diagnóstico de las condiciones actuales de producción del GGAVATT,
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.