Enhancing milk and fertility performances using selection index developed for Indian Murrah buffaloes

Selection for genetically superior Murrah buffaloes under Network Project on Buffalo Improvement, India, is presently based on milk yield, and it was observed that even in the absence of any direct selection pressure applied on fertility, there has been a downward trend in fertility associated with the selection for milk yield. The aim of the study was to develop selection indices which include fertility besides milk yield in Murrah buffaloes. Data pertaining to 1,224 lactation records spread over a period of 19 years were recorded and analyzed in the study. The negative association of pregnancy rate (fertility) with a 305-day milk yield (?0.08?±?0.04) and wet average (?0.12?±?0.02) indicated the importance of incorporating fertility trait in the construction of selection index. Four types of selection indices were constructed and evaluated. Two indices were developed using expected producing ability 305-days milk yield (EPAMY) with 6.5 and 4 % fat in milk along with expected fertilizing ability (EFA). The other two indices developed consist of expected producing ability wet average (EPA WA) and EFA. The index involving (EPA WA and EFA) was found to be a more effective selection criterion in our herd, as the accuracy of index was more (0.61), in comparison to the index involving EPA MY and EFA. The robustness of selection index was assessed by increasing the relative economic values of included traits by 25 and 50 %, and accuracy of the index remains almost stable without much change. The developed selection strategy involving EPA WA and EFA should be considered for the genetic evaluation of Murrah buffaloes, as it has a potential for maximizing the lifetime reproduction and production performances of the breed.     

Effect of exogenous fibrolytic enzymes supplementation on milk production and nutrient utilization in Murrah buffaloes

The present study was conducted to evaluate the effect of commercial exogenous fibrolytic enzyme (EFE) mixture added at 1.5 and 3.0 g (cellulase 4,000 μM glucose/g/h + xylanase 7,990 μM xylose/g/min; 50:50 w/w) per kilogram of dry matter (DM) of feed on nutrient digestibility, milk production, milk composition, and some blood constituents in lactating Murrah buffaloes. Eighteen buffaloes were allotted to three dietary treatments, on the basis of milk yield (8.48, 8.52, and 8.53 kg/day) and days in lactation (68.5, 80.33, and 82.00) for 90 days. The buffaloes were fed a total mixed ration (TMR) comprising of 45% chaffed wheat straw, 15% chopped green maize, and 40% concentrate on DM basis (control group), the same TMR plus EFE at 1.5 g/kg DM (T-1 group) and the same TMR plus EFE at 3.0 g/kg DM (T-2 group) supplemented through the concentrate mixture. There was no effect of fortifying EFE mixture on DM intake and crude protein intake (grams per day) whereas total digestible nutrients intake (kilogram per day) was higher by (P < 0.05) 12.53% in T-1 group over that of control, and there was no significant difference between T-2 and control groups. The average daily milk yield and 4% fat-corrected milk (FCM) yield was higher (P < 0.05) by 12.99% and 15.17% in T-1 group as over that of control, and there was no difference between T-2 and control groups. There was no (P > 0.05) difference in blood glucose and blood urea nitrogen concentration in different experimental groups. It is concluded that supplementation of cellulase and xylanase mixture at 1.5 g/kg of DM of TMR containing wheat straw (45%), green maize (15%), and concentrate (40%) on DM basis significantly increased (P < 0.05) the average daily milk yield and FCM yield in Murrah buffaloes due to improved dietary fiber digestion.     

In vitro phagocytic activity of milk neutrophils during lactation cycle in Murrah buffaloes of different parity

Milk samples were collected from 34 lactating Murrah buffaloes on days 0, 5, 15, 30, 45, 60, 90, 120, 150, 180, 210, 240, 270 and day 300 after calving. Milk somatic cell counts (SCC) were highest in multiparous buffaloes . Milk SCC were significantly lower in buffaloes of third and fourth parity during early lactation and than increased significantly (p < 0.01) by the end of lactation. Milk neutrophils were significantly lower in all the buffaloes during early lactation, but increased significantly (p < 0.01) afterwards. Milk lymphocytes were significantly higher during early lactation, but decreased significantly (p < 0.01) by the end of lactation. Phagocytic activity (PA) was highest in day 1 colostrum and then decreased significantly (p < 0.01) by the fourth milking in buffaloes of second, third and fourth parity . Phagocytic index (PI) was also highest in colostrums of primiparous buffaloes. Irrespective of parity, maximum PA and PI was observed during mid lactation. In terms of in vitro phagocytic activity, early lactation is the most critical period followed by late and mid lactation.     

A review of major histocompatibility complex-disease associations in man and dog

The organization and biology of the Major Histocompatibility Complexes (MHC) of man (HLA) and dog (DLA) are reviewed, and a summary is presented of laboratory techniques used to define allotypes.The nomenclature of this field and the mechanisms of disease association with the MHC are discussed. Currently recognized HLA-disease associations are enumerated, with emphasis on the value of the complement C4 marker.DLA-disease association studies into autoimmune disease, allergy and neoplasia are reviewed.     

Immunogenetics and the major histocompatibility complex.

The poultry immune system is a complex system involving many different cell types and soluble factors that must act in concert to give rise to an effective response to pathogenic challenge. The complexity of the immune system allows the opportunity for genetic regulation at many different levels. Cellular communication in the immune response, the production of soluble factors, and the rate of development of immune competency are all subject to genetic influences. The genes of the major histocompatibility complex (MHC) encode proteins which have a crucial role in the functioning of the immune system. The MHC antigens of chickens are cell surface glycoproteins of three different classes: Class I (B-F), Class II (B-L) and Class IV (B-G). The MHC antigens serve as essential elements in the regulation of cell-cell interactions. The MHC has been shown to influence immune response and resistance to autoimmune, viral, bacterial and parasitic disease in chickens. The MHC has been the primary set of genes identified with genetic control of immune response and disease resistance, but there are many lesser-characterized genes outside of the MHC that also regulate immunoresponsiveness. Polygenic control has been identified in selection experiments that have produced lines of chickens differing in antibody levels or kinetics of antibody production. These lines also differ in immunoresponsiveness and resistance to a variety of diseases. Understanding the genetic bases for differences in immunoresponsiveness allows the opportunity selectively to breed birds which are more resistant to disease. Indirect markers that can be used for this selection can include the MHC genes and immune response traits that have been associated with specific or general resistance to disease.     

Relationship of temperament with oestrous behaviour,resumption of ovarian cyclicity and milk yield in post‐partum Murrah buffaloes

This study was designed to investigate the relationship of temperament with oestrus, resumption of ovarian cyclicity and milk yield in post‐partum buffaloes. For this study, 102 post‐partum Murrah buffaloes were observed for temperament in open paddock and during milking. Based on the temperament score (1–5 score), they were classified into docile, slightly restless, restless, aggressive and nervous. Oestrous behaviour was monitored twice daily in all the buffaloes along with milk yield (weekly), body weight (BW) and body condition score (BCS) at day 0, 30, 60 and 90 post‐partum. Based on the temperament score, the number of buffaloes classified as docile, slightly restless, restless and aggressive was 37 (36.27%), 28 (27.45%), 30 (29.41%) and 7 (6.86%), respectively, but none under nervous category. Number of buffaloes resuming cyclicity in various temperaments groups were as follows: docile (n = 35; 94.59%), slightly restless (n = 22; 78.57%), restless (n = 20; 66.67%) and aggressive (n = 7; 85.71%). Temperament was not correlated (p = .128; r=?.152) with oestrous behaviour. But, temperament was correlated (p < .0001; r = .384) with the resumption of cyclicity as docile and slightly restless buffaloes resumed cyclicity (p < .0016) earlier. Temperament of buffaloes was weakly correlated (p = .0017; r=?.306) with milk production with higher (p < .0358) total milk yield in docile (1022 ± 23.75 kg) and slightly restless buffaloes (948 ± 35.86 kg) as compared to other temperament groups. In summary, temperament of post‐partum buffaloes was related with resumption of ovarian cyclicity and milk yield, but not oestrous behaviour.     

Normal somatic cell count and subclinical mastitis in Murrah buffaloes

This study was conducted to investigate the normal somatic cell count (SCC) and to define subclinical mastitis in Murrah buffaloes. Data were collected from 60 clinically normal buffaloes stationed at five farms of Chitwan Nepal and Buffalo Research Center, Hissar, India. Somatic cell count was measured using the Newman-Lampert staining technique. The upper limit of SCC was determined >or=200 000/ml of milk based on the mean +/- 2SD of a total SCC. Abnormal data of the SCC was repeatedly removed, which lie beyond the values of more than mean + 2SD until all the data come to lie within (mean + 2SD). Averages of SCC of right front and right hind quarters were significantly higher than left front and left hind quarters. Nearly 94% of California mastitis test (CMT) negative quarters were having somatic cells >or=200 000/ml. The mean SCC of CMT positive quarter was significantly higher (P < 0.01) than CMT negative quarters. Subclinical mastitis was diagnosed on the basis of samples with SCCs >or=200 000/ml with positive bacterial cultures. Subclinical mastitis was found in 21.7% buffaloes and 8% of the quarter foremilk samples. Neutrophil counts were significantly higher in subclinical mastitis milk.     

A human major histocompatibility complex (MHC) DNA probe recognizes goat genes

A human major histocompatibility complex (MHC) class II (DR-β) probe was hybridized with restriction enzyme digest of genomic DNA from 14 goats. Nine of the animals belonged to one family. Digestion of the DNA with the restriction enzyme Eco RI gave 7 fragments in 13 animals and 6 fragments in the last animal. No other polymorphism could be detected. Bam HI digestion gave from 3 to 6 fragments which displayed a considerable polymorphism. In the family studied, polymorphic fragments were inherited together with serologically defined lymphocyte antigen specificities believed to be coded for by MHC class I genes.     

Housing of Norwegian goat herds and associations with milk yield and milk quality

Abstract

Data from a questionnaire regarding housing factors were merged with data from the milk recording databases (herd mean annual milk yield per goat, somatic cell count (SCC) and bulk milk bacterial count), and the material included 235 herds. Associations with housing factors were tested at herd level and at individual goat level. Housing in insulated buildings with no access to outdoor areas during the winter season, expanded metal grating and no use of bedding predominated. None of the housing factors evaluated were significantly associated with milk yield. In herds using water nipples, SCC was lower compared to herds using water bowls. SCC was also lower in herds with milking facilities in separate milking stalls as compared with combined feeding milking stalls in common pens. No significant associations were found between housing factors and bacterial counts, but the counts were lower in herds with high average milk yields per goat.     

Random regression models to estimate genetic parameters for test‐day milk yield in Brazilian Murrah buffaloes

The objective of this work was to estimate covariance functions for additive genetic and permanent environmental effects and, subsequently, to obtain genetic parameters for buffalo’s test‐day milk production using random regression models on Legendre polynomials (LPs). A total of 17 935 test‐day milk yield (TDMY) from 1433 first lactations of Murrah buffaloes, calving from 1985 to 2005 and belonging to 12 herds located in São Paulo state, Brazil, were analysed. Contemporary groups (CGs) were defined by herd, year and month of milk test. Residual variances were modelled through variance functions, from second to fourth order and also by a step function with 1, 4, 6, 22 and 42 classes. The model of analyses included the fixed effect of CGs, number of milking, age of cow at calving as a covariable (linear and quadratic) and the mean trend of the population. As random effects were included the additive genetic and permanent environmental effects. The additive genetic and permanent environmental random effects were modelled by LP of days in milk from quadratic to seventh degree polynomial functions. The model with additive genetic and animal permanent environmental effects adjusted by quintic and sixth order LP, respectively, and residual variance modelled through a step function with six classes was the most adequate model to describe the covariance structure of the data. Heritability estimates decreased from 0.44 (first week) to 0.18 (fourth week). Unexpected negative genetic correlation estimates were obtained between TDMY records at first weeks with records from middle to the end of lactation, being the values varied from ?0.07 (second with eighth week) to ?0.34 (1st with 42nd week). TDMY heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in milking buffaloes.     

Plasma hormones, metabolites, milk production, and cholesterol levels in Murrah buffaloes fed with Asparagus racemosus in transition and postpartum period

Ten dry and pregnant Murrah buffaloes were selected to investigate the effect of Asparagus racemosus feeding on hormones, metabolites, milk yield, and plasma cholesterol levels. The treatment groups of buffaloes were fed with A. racemosus (shatavari) @?150?g/day/animal during prepartum and @?300?g/day/animal during the postpartum period. Blood samples collected on ?6, ?4, ?2-week, day of parturition (0), and +2, +4, and +6-week postpartum were analyzed for plasma total cholesterol, triglycerides, HDL, low-density lipoproteins (LDL), prolactin, cortisol, and blood metabolites. Milk samples collected at weekly intervals (+1, +3, +5, and 7?weeks) were analyzed for total milk fat cholesterol. Prepartum plasma cholesterol concentrations were significantly higher in treatment group over the control (P?<?0.05). Mean plasma triglycerides, LDL cholesterol, HDL cholesterol, glucose, and nonesterified fatty acid (NEFA) levels varied nonsignificantly between groups. Plasma prolactin and cortisol concentrations were significantly (P?<?0.01) more in treatment group than in control group. On day of parturition, plasma prolactin, cortisol, LDL, and plasma total cholesterol were higher (P?<?0.01) in treatment group buffaloes in comparison to control group. A. racemosus feeding significantly (P?<?0.01) increased plasma prolactin, cortisol (P?<?0.01), and milk fat cholesterol (P?<?0.05) without affecting total cholesterol, HDL, LDL, glucose, and NEFA concentrations. The buffaloes of treatment group produced more milk (?@?0.526?kg/animal/day) suggesting thereby that A. racemosus is galactopoietic. It was concluded that feeding of A. racemosus increases plasma prolactin and cortisol and decreased plasma total cholesterol and LDL concentration.     

Accuracy of pregnancy/non pregnancy diagnosis in zebu and crossbred cattle and Murrah buffaloes by milk progesterone determination post insemination

Tropical Animal Health and Production - Milk samples collected on days 0, 6, 20, 22 and 24 post insemination from Sahiwal and Tharparkar (zebu) cows, Karan Swiss (Sahiwal × Brown Swiss) and...     

Effect of rumen-protected nutrients on feed intake,body weights,milk yield,and composition in Murrah buffaloes during early lactation

The effect of rumen-protected nutrients (bypass fat, BPF; bypass protein, BPP; or their combination, BPPF) was investigated in Murrah buffaloes during the early stage of lactation. Forty Murrah buffaloes (BW 531.92?±?10.85 kg) just after parturition were randomly distributed into four groups according to parity and milk production. Buffaloes individually fed ration from day 0 to 90 postpartum according to feeding group and nutrient requirement. Control and BPF fed groups received a concentrate mixture, CM1 with 25% rumen-protected protein (using barley, wheat bran, and mustard oil cake), BPP and BPPF groups received a second concentrate mixture, CM2 with 40% rumen-protected protein (using barley, de-oiled rice bran, and cottonseed cake). Bypass fat fed groups (BPF and BPPF) additionally were supplemented with 15 g BPF (Ca salt of long-chain fatty acids) per kg milk yield in their respective concentrate mixtures. Dry matter intake, body weights, body condition score, and total milk yield were similar between groups (P?>?0.05). Fat-corrected milk (FCM) production was improved (14.5%, P?>?0.05) in groups fed BPP and BPPF, while significant (19.45%, P?<?0.05) improvement was observed in BPF-fed group. Overall mean values of milk fat, solid not fat, protein, lactose, and total solids were found to be high (P?<?0.05) in treatment groups as compared with control values. It may be concluded that supplementation with BPP or BPF either alone or in combination positively influences the quality of milk produced in Murrah buffaloes during early lactation and BPF additionally had improvement on the quantitative trait of milk as well.

     

The evolution and maintenance of polymorphism in the major histocompatibility complex

Lambs with the G2 allele at the ovine major histocompatibility complex (mhc) class II locus DRB1 has previously been shown to have lower faecal nematode egg counts than lambs with the I allele at this locus. This association has been confirmed in separate cohorts from the same farm. Other alleles within the mhc have also shown associations with nematode resistance in other breeds of sheep. Therefore, variation in the mhc is responsible for part of the observed genetic variation in resistance to nematode infection. In addition to the specific effect of particular alleles, heterozygotes are also more resistant than homozygotes. This heterozygote advantage is capable of maintaining the high levels of polymorphism observed within the mhc.     

Structure and function of the major histocompatibility complex in domestic animals

The major histocompatibility complex (MHC) is a genetic region that has been intensively studied for the past 2 decades. Interest in the MHC has been high because of (i) the particular involvement of the MHC in transplantation reactions, including organ allograft rejection in human beings; and (ii) the more general role of MHC gene products in the genetic control of immune responses in all mammals. The MHC has several remarkable properties that include a distinctive genetic structure which has been well-preserved through evolution, and the extreme plasticity of form of the principal MHC genes, which can coexist within a single species in 30 or more allelic forms. The genes of the MHC regulate cell-cell interactions of various types within the lymphoreticular system, and thus function as the so-called "immune response" genes that have been described in mice, rats, and guinea pigs. In human beings, the "disease associations" demonstrated between MHC alleles and various pathologic conditions are probably manifestations of abnormal functions of immune regulation governed by the MHC. Studies of the MHC in domestic species are still in their infancy. However, investigations of the MHC have been carried out in swine, cattle, horses, sheep, goats, dogs, and chickens. Further research on the MHC of domestic animals is merited, both for its contribution to the overall understanding of the biological significance of the MHC and for its practical application in clinical veterinary medicine.     

Studies on cisternal and alveolar fractions &; its composition and mammary health of Murrah buffaloes administered oxytocin

The study was conducted on 18 lactating Murrah buffaloes in 83.72 ± 14.75 days after calving. Group I buffaloes were not injected with oxytocin and served as control. Buffaloes of Group II were injected with oxytocin @ 2.5 IU per 0.5 ml intramuscularly at the hip region for a period of 1 month while Group III buffaloes received injection of oxytocin @ 5.0 IU per ml intramuscularly at the hip region for a period of 1 month. Milk samples from three groups of buffaloes were collected after oxytocin injections at 15 days interval on 0, 15, 30 and 45 days. Blood samples were collected in heparinized tubes at 0, 15, 30 and 45 days of experiment from all three groups of buffaloes. There was no significant change in cisternal, alveolar and total milk yield by exogenous oxytocin administration. Fat % in cisternal, alveolar and total milk decreased significantly (P < 0.01) by 11.8% and 21.3% in groups II and III buffaloes, respectively. Protein % increased significantly (P < 0.01) in group III. A significant increase was observed in somatic cell counts of milk by 5.36% and 6.22% in groups II and III, respectively as compared to control group. Part of MV. Sc. Thesis of the first author submitted to National Dairy Research Institute (Deemed University)     

3个绵羊种群MHC微卫星标记的遗传多样性

利用微卫星技术对小尾寒羊、道赛特羊、特克赛尔羊3个绵羊种群共218只绵羊的主要组织相容性复合体（MHC）ClassⅡ区DRB1、DRB2、DYMS、MB026基因座的微卫星多态性进行了研究。统计了3个种群的等位基因组成,并计算了微卫星基因座的等位基因频率、杂合度和多态信息含量。结果显示,4个基因座在3个种群中的平均等位基因数分别为14、10.33、12.67、5.33个;平均多态信息含量分别为0.8315、0.8037、0.7946、0.3992;平均杂合度分别为0.8473、0.8229、0.8165、0.4202。研究结果说明,DRB1、DRB2、DYMS基因座为高度多态基因座,MB026基因座为中度多态基因座,在这4个微卫星基因座上,小尾寒羊、道赛特羊及特克赛尔羊均具有丰富的遗传多态性,可作为有效的遗传标记用于各绵羊品种的遗传多样性和系统发生关系分析。