Study on reproductive performance of Holstein–Friesian dairy cows at Alage Dairy Farm,Rift Valley of Ethiopia

A retrospective study was carried out to evaluate the reproductive performance of Holstein–Friesian cattle in Alage Dairy Farm in the Rift Valley of Ethiopia using data recorded from July 1983 to June 2005. Data of cows with complete information were considered, and a total of 1,104 records for calving to conception (Cal-Con), calving interval (CI), and number of services per conception (NSC), and 721 records for age at first service (AFS) and at first calving (AFC) were analyzed. The overall means (±S.E.) of AFS, AFC, Cal-Con and CI, and NSC were 991.4 ± 24.3, 1,265 ± 24.3, 285.8 ± 18.9, 561.3 ± 18.9 days and 1.69 ± 0.1, respectively. Parity significantly influenced NSC, Cal-Con, and CI. Season and year showed a significant effect on all the parameters, indicating the role of the environment and more specifically the influence of nutritional conditions at least for the long AFS and AFC, management practices, and climate on reproductive performance of the study herd. A more focused study to discern the elements of the reproductive constraints have been recommended.     

Influence of fibrolytic enzymes in total mixed ration containing urea-molasses-treated sugarcane bagasse on the performance of lactating Holstein–Friesian crossbred cows

The aim of this study was to determine the effect of different levels of fibrolytic enzyme on nutrient utilization and milk production in dairy cows. Four multiparous early-to-mid-lactation Holstein–Friesian crossbred cows were randomly allocated in a 4 × 4 Latin square design. Cows were fed a balanced total mixed ration (TMR) on a dry matter (DM) basis containing 0, 1.2, 2.4, and 3.6 g/kg DM of fibrolytic enzyme in TMR, where the TMR comprises 60% concentrate supplemented with a fibrolytic enzyme at 0, 2, 4, and 6 g/kg DM of concentrate, and 40% urea-molasses-treated sugarcane bagasse (UMSB) was used as a roughage source. Fibrolytic enzyme supplementation in TMR containing UMSB did not affect dry matter intake (DMI) of dairy cows (p > 0.05). There was a quadratic effect of fibrolytic enzyme levels on the digestibility of DM, organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) (p < 0.05), and the maximal response was reached at 1.2–2.4 g/kg DM of fibrolytic enzyme added in the TMR. Furthermore, 3.5% fat-corrected milk, milk fat, total volatile fatty acids, and propionic acid were greater in a cow fed with 1.2–2.4 g/kg DM of fibrolytic enzyme, resulting in a lower ratio of acetic acid to propionic acid (p < 0.05). In conclusion, adding a fibrolytic enzyme in TMR containing UMSB improved nutrient utilization, rumen fermentation, and milk production of lactating dairy cows.     

Genetic variation in serological response to Mycobacterium avium subspecies paratuberculosis and its association with performance in Irish Holstein–Friesian dairy cows

Paratuberculosis, also referred to as Johne's disease, is a contagious and chronic disease in ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). Few estimates of the genetic variation in measures of susceptibility to MAP are available in the literature and even less have attempted to elucidate the genetic associations between measures of susceptibility to MAP and performance in dairy cattle. The objectives of this study were to estimate the genetic variation in serological response to MAP in 4789 Holstein–Friesian dairy cows from 44 Irish dairy herds, and to quantify its genetic association with performance traits measured in the first three lactations of genetically related animals. Univariate mixed linear and threshold animal models were used to estimate variance components and genetic correlations were estimated using bivariate animal linear mixed models; MAP serological response was treated as a continuous variable and dichotomous variable. The prevalence of MAP in the sample population was 4.4%. This figure cannot be extrapolated to the national dairy herd as the sample population was biased towards herds with increased likelihood of MAP infection. Estimates of heritability for MAP serological response varied from 0.07 to 0.15 depending on the model of analysis and whether serological response was treated as continuous or binary; standard errors varied from 0.024 to 0.062. Genetic correlations between MAP serological response and lactation milk, fat and protein yield were negative or close to zero although not always more than two standard errors from zero; stronger negative genetic correlations were evident in older parity animals. Serological response to MAP was not genetically correlated with milk fat concentration but was positively genetically correlated with milk protein concentration in first lactation and negatively correlated with calving interval. There was little or no genetic association between serological response to MAP and survival. Results from this study corroborate previous international suggestions that selection for reduced serological response to MAP is possible, although this does not necessarily imply a concurrent selection for either reduced prevalence of clinical disease or increased resistance to MAP infection.     

Udder health in relation to udder and teat morphometry in Holstein Friesian × Sahiwal crossbred dairy cows

The present investigation involved 261 Holstein Friesian (HF) × Sahiwal cows to study the udder health as well as the udder and teat morphometry. The udder health was defined on the basis of bacteriology and California mastitis test of quarter foremilk. The morphometry parameters included udder fore depth (UFD, distance from the point where the fore udder merges within the abdomen to a point in front of the fore teats at the level of the udder base), udder rear depth (URD, distance from the bottom of the vulva to the base of the rear udder), udder depth (UD, level of the udder base with respect to hock joint), height of the udder from the floor, teat length, teat diameter (at mid of the teat barrel), teat-tip to floor distance and distance between the teats. The URD, UD and height of udder from the floor showed a significant (P?<?0.05) relation to the udder health with mastitic cows having larger URD, smaller udder distance from the floor and the udder base placed below the hock joint. The cows with teat length larger than 4.5 cm and teat diameter 3.0 cm or larger had significantly more quarters affected with mastitis. Further, cows with teats placed nearer to the floor were more susceptible to mastitis (P?<?0.01). No significant differences were found between healthy and mastitic udders with respect to UFD and distance between teats. It can be concluded that selection for optimum udder and teat morphometry in breeding programmes may help to reduce susceptibility to intramammary infections in HF × Sahiwal cows.     

Evaluation of ultrasonography for measuring solar soft tissue thickness as a predictor of sole ulcer formation in Holstein–Friesian dairy cows

The aim of this research was to investigate the correlation between the thickness of solar soft tissue (SST; i.e. the corium and subcutaneous tissue) in early lactation and sole ulcer formation in late lactation. Fifty Holstein–Friesian cows were examined three times: (1) 30 days after calving (locomotion scoring, trimming, claw examination, measurement of SST); (2) 70 days after calving (locomotion scoring); and (3) 180 days after calving (locomotion scoring, trimming, claw examination).SST thickness was measured using an 8 MHz linear probe, at two points (SST1 below the apex of the pedal bone, and SST2 below the flexor tubercle). Mean values for SST1 and SST2 were 3.26 ± 0.43 mm and 4.35 ± 0.46 mm, respectively; the two measures were positively correlated (r = 0.95, P < 0.001). At 180 days after calving, a sole ulcer was diagnosed in 12/50 cows (24%). Cows with a thinner SST had a higher risk of developing sole ulcers than those with a thicker SST. The optimal cut-off values of SST1 and SST2 in predicting cows with sole ulcers (as calculated by ROC analysis) was ?3 mm for SST1 and ?3.9 mm for SST2. The relative risk of a sole ulcer developing, based on those cut-off values was 4.25 (95 CI, 1.77–24.88) for SST1 ? 3 mm and 3.63 (95 CI, 1.18–10.8) for SST2 ? 3.9 mm.     

Congenital tremor in Holstein Friesian‐cattle

Summary

In a female family line of Holstein‐Friesian cattle a series of trembling calves was born within a period of ten years. All trembling animals were male; female calves appeared normal At necropsy of one calf severe degenerative lesions of spinal cord and brain white matter were observed Both myelin and axons were lost and some macrophages occurred within digestion chambers. Obviously degenerated neurones were not found The lesion was interpreted as a single recessive sex‐linked hereditary trait.     

Reproductive Responses of Holstein–Friesian Cattle to the Climatic Conditions of Central Sudan

Data were evaluated from a purebred Holstein herd (n = 1274) kept near Khartoum, a hot and dry area, from 1990 to 1996. The mixed model procedure in SAS was used to analyse the reproductive traits. The mean gestation length, days dry, number of services per conception, days from calving to first oestrus, days from calving to conception, calving interval and breeding efficiency were 279 days, 104 days, 4.2, 85.8 days, 208.9 days, 486.2 days and 74.9%, respectively. Factors that had significant effects (p<0.01) on all the reproductive measures under study were the year and month of calving, and parity.The heritability estimates for all traits under investigation were zero. The repeatability estimates for the numbers of services per conception, days from calving to conception, days from calving to first oestrus and calving interval were 0.21±0.021, 0.12±0.024, 0.03±0.018 and 0.00, respectively. The phenotypic correlation for calving interval with numbers of service per conception was 0.05, that with days from calving to first oestrus was 0.06 and that with days from calving to conception was 0.07. Other correlations ranged from 0.00 to 0.28. The simple correlation coefficients between production and reproductive measures ranged from –0.06 to 0.45.     

Postpartum toll-like receptors and β-defensin 5 mRNA levels in the endometrium of Holstein cows

Toll-like receptors (TLRs) and β-defensins are important components of the innate immune system. This study aimed to evaluate endometrial mRNA levels of TLRs (1/6, 2, 4, and 5) and β-defensin 5 in Holstein cows by quantitative real time RT-PCR. Uterine biopsies were performed from 6 to 12 h after parturition, and cows were divided into two groups: (i) cows with placental retention and clinical signs of uterine infection until 45 days postpartum (n=10) or (ii) cows with normal puerperium (n=10). All cows had detectable levels of TLRs and β-defensin 5 mRNAs, but these levels did not differ between groups (P>0.05). Levels of TLR4 mRNA had a positive and significant correlation with the time required for uterine involution in both groups.     

Polymorphism of the beta-casein gene and its associations with breeding value for production traits of Holstein–Friesian bulls

Beta-casein A1 protein variant might be one of the risk factors in the etiology of human disorders like diabetes and ischemic heart disease. However, from the practical perspective selecting for the A2 allele in dairy cattle requires knowledge of whether the A1/A2 polymorphism is associated with breeding values for production traits. A DNA fragment containing A1/A2 polymorphic region was amplified and genotyped using the PCR-ACRS (Amplification Created Restriction Site) technique in 478 Holstein–Friesian bulls yielding the allele frequencies of 0.35 and 0.65 for the A1 and the A2 variants, respectively. A linear regression model was used for testing the association between the polymorphism and breeding values for production traits and showed that the allele coding the A2 protein variant increases breeding values for milk and protein yield and decreases breeding values for fat percentage in milk. Genotyping A.I. bulls at beta-casein locus and preferring A2 allele may lead to two benefits: increasing breeding value for protein yield and decreasing frequency of A1 protein variant, being considered as risk factor for human health.     

Calf morbidity and mortality in smallholder dairy farms in Ada’a Liben district of Oromia,Ethiopia

A longitudinal observational study on calf morbidity and mortality was conducted in smallholder dairy farms in Ada’a Liben district of Oromia, Ethiopia. A total of 185 calves from 112 market oriented smallholder dairy farms were selected randomly and regularly monitored for clinical health problems up to six months of age. Information on potential risk factors was collected by personal observation during the regular visit to farms and from questionnaire survey conducted during the study period. The overall incidences of crude morbidity and crude mortality were 62 % and 22%, respectively. The most frequent disease syndrome was calf diarrhea with the incidence of 39% followed by joint ill 6%. The other disease conditions/syndromes diagnosed include navel ill, pneumonia, septicemic conditions, congenital problems and miscellaneous cases. Age of the calves, age at first colostrum ingestion and cleanness of the calf barns significantly influenced morbidity. Older calves (greater than three months of age) were at lower risk of crude morbidity than younger calves (less than three months of age) (HR = 0.42, P = 0.001). Higher risk of crude morbidity was observed in calves that ingested their first colostrum meal later than 6 hours of age compared to those that ingested colostrum earlier (HR = 2.24, P = 0.001). Similarly, calves housed in unclean barns were at higher risk of morbidity than calves housed in clean barns (HR = 1.75, P = 0.024). Of the 20 potential risk factors investigated, age was the only factor that was found significantly associated with mortality (HR = 0.04, P = 0.001). Calves older than three months of age were at lower risk of mortality than younger calves.     

Genetic and Environmental Effects on the Productivity of Holstein–Friesian Cattle under the Climatic Conditions of Central Sudan

A herd of 370 Holstein–Friesian cows were maintained in Central Sudan, Khartoum for intensive dairy production during the period 1990–1996. The area is characterized by high temperatures during the day and cools down at night, with an average thermal-humidity index (THI) of 74.8. The average adjusted lactation milk yield, milk yield per day, milk yield per day of calving interval and lactation length of the animals in the herd were 5117±123 (SE) kg, 14.7±0.25 kg, 11.3±0.36 kg and 350±8.0 days, respectively. Heifers calved at 25.2±2.3 (SD) months of age. The variation was large, which suggested large environmental fluctuations. Sire variance contributed 1.35% and 19.6% to the total variance in cows and heifers, respectively, while cow within sire contributed 19%. The heritabilities of total lactation yield, 305-day yield, milk per day of lactation, milk per day of calving interval, and lactation length in heifers were 0.78±0.24, 0.36±0.34, 0.39±0.24, 0.23±0.23, and 0.23±0.22, respectively. In cows, the heritability estimates were 0.05±0.24, 0.06±0.24, 0.08±0.24, 0.00 and 0.00 for the same traits, respectively. The repeatabilities of total lactation yield, 305-day yield, milk per day, milk per day of calving interval and lactation length were 0.02±0.03, 0.22±0.03, 0.17±0.02, 0.05±0.02 and 0.00, respectively. Regression analysis showed that, for each unit increase in THI, milk yield decreased by 0.29±0.04 kg. The stress usually caused by the combined effects of temperature and humidity was not severe in this area.     

Farmers’ perceptions of the causes of low reproductive performance in cows kept under low-input communal production systems in South Africa

The objective of the study was to determine farmers’ perceptions of the causes of low reproductive performance in Nguni cows raised on communal rangelands in the Eastern Cape Province of South Africa. Data were collected using participatory rural appraisals and structured questionnaires that were administered to 551 randomly selected farmers from ten communities in the Eastern Cape. Cattle herd sizes ranged from 3 to 11 and were mainly composed of cows. Cattle sales were ranked as the most important use of cattle in all the villages. Tick-borne diseases and poor animal condition were reported as chief constraints of cattle production in most communities. More than 60% of the interviewees reported that the age at puberty and age at first calving for their cows varied between 18 and 36, and 24 and 48 months, respectively. About 95% of the respondents reported long calving intervals and low bull numbers as major causes of low reproductive performance in cows in the communal areas. It was concluded that farmers perceived delayed age at puberty and at first calving, long calving intervals and low bull numbers as the major causes of low reproductive performance in Nguni cows raised on communal rangelands in South Africa.     

Voluntary intake and milk production in F1 Holstein × zebu cows in confinement

The objective of this study was to evaluate the nutrient intake and milk production in Holstein × zebu (F1) cows in feedlot. Eighteen F1 cows were used, divided into three treatments; six were Holstein × Gir (HGI), six were Holstein × Guzerat (HGU), and another six were Holstein × Nelore (HNE), which had recently calved, distributed into simple, random samples, under the same feeding conditions of corn silage and concentrate with 20% crude protein. The three-marker method was used (LIPE, titanium dioxide, and iADF) to estimate the individual intake and digestibility of the nutrients for the cows in group. The mathematical model used to establish the lactation curves was: Y = at(b)e(-ct) by Wood (Nature 216:164-165, 1967). The statistical analyses for the nutrient intake and digestibility, as well as parameters of metabolic efficiency, were performed using multiple linear regression (α = 5%). No effect (P > 0.05) of genetic group was observed for any of the variables studied. The intake and digestibility of the nutrients and the microbial nitrogen presented quadratic curves as a function of the lactation period (P < 0.05). The HGU cows exhibited an accumulated milk production of 4,946.81 kg at 305 days, whereas the HGI cows produced 4,821.78 kg. The HNE cows displayed inferior performance, with a production of 3,674.98 kg. It was concluded that, in confinement, F1 cows from different genetic groups do not exhibit different intake, digestibility, or metabolic efficiency. The HGU and HGI cows have greater cumulative production at 305 days.     

The effect of non-genetic factors on the reproductive performance of Sanga and Friesian × Sanga crossbred dairy cattle breeds kept under hot and humid environment

A study was conducted to assess the effect of non-genetic factors on the reproductive performance of Sanga and Friesian?×?Sanga crossbred dairy cattle kept at Amrahia Dairy Farm, Ghana. Records on 66 crossbred Friesian?×?Sanga and 105 purebred Sanga cattle from 2005 to 2012 were used. The effect of sex of calf (male or female), season of calving (major, minor and dry), year of calving (2005–2012) and parity (first to third) on birthweight, calving interval and age at first calving were determined. The data were analyzed using the general linear model procedures of GenStat (Discovery Edition). The effect of parity of dam, year of calving, season of calving and sex of calf were considered as fixed effects for evaluating the different reproductive traits. Data on calving and conception rates over the period were 74.3 and 76.1 %, respectively. The overall mean values for birthweight, age at first calving and calving interval obtained were 23.9?±?1.5 and 22.8?±?1.4 kg, 38.8?±?2.5 and 40.2?±?2.4 months and 390.8?±?12.5 and 413.6?±?12.1 days for the crossbred and Sanga, respectively. It was observed that all the major determinants of reproductive performance studied apart from birthweight were significantly influenced by year of birth, parity, season of calving and sex.     

Seroprevalence of Neospora caninum antibodies and its consequences for reproductive parameters in dairy cows from Dakar–Senegal,West Africa

The aim of this study was to determine the seroprevalence of Neospora caninum antibodies and its effects on reproductive parameters in cows in intensive dairy herds in Dakar. Randomised blood samples were taken for serology from 196 cows in four herds with a history of sporadic abortion. All of the sera were assayed for antibodies against N. caninum, Candida guillermondii, Coxiella burnetii, and Chlamydophila sp. The associations between serostatus and reproductive parameters (abortion, number of inseminations to conception, and calving to conception interval) were assessed over a period of 5 years (2004–2008). The seroprevalence of N. caninum antibodies in dairy cattle was 17.9%. The local Gobra breed and crossbreeds had higher levels of N. caninum antibodies than exotic breeds (p < 0.05). For the most recent pregnancies, seropositive cows required more inseminations to establish conception than seronegative cows (p < 0.05). The results indicate that dairy cattle from Dakar are exposed to N. caninum. Neosporosis should, therefore, be systematically considered as a cause when the calving to conception interval is prolonged.     

Serological and parasitological survey of dourine in the Arsi–Bale highlands of Ethiopia

This study was conducted from August 2005 to January 2007 to determine prevalence and distribution of dourine in horses and to investigate the occurrence of clinical and carrier cases in donkeys and mules in the Arsi–Bale highlands. Study methodology was based on questionnaire, serological, clinical and parasitological survey. The questionnaire indicated that dourine is a major health problem of equines in the Arsi–Bale highlands. Though dourine is commonly observed throughout the year, it has a seasonal character and occurs mostly during the breeding season from June to late September. Serological screening of 646 horses showed a seroprevalence of 184 (28%), 161 (25%) and 125 (19%) for card agglutination test for trypanosomosis, LATEX and enzyme-linked immunosorbent assay, respectively. Risk factors were parity number, previous history of abortion and body condition score. No trypanosomes could be detected by Giemsa staining or by haematocrit centrifugation technique. Ten puppies inoculated with blood samples, genital washes and oedematous fluids remained parasitologically negative. Different characteristic signs of dourine were observed. During the genital stage, mares showed vaginal oedema, discharge and presence of depigmented scars over the external genitalia. In stallions, oedema of the scrotum and prepuce, prepucial and urethral discharge, and ulceration of the genital mucosae mainly of the penile were observed. In both sexes, lameness in one or both legs, partial dragging and stiffness of the hind legs and incoordination were the dominant signs observed as nervous form of the disease.     

Investigation of Marek’s disease virus from chickens in central Ethiopia

Marek’s disease (MD) is a lymphoproliferative and neuropathic disease of domestic chickens and less commonly, turkeys and quails, caused by a highly contagious, cell-associated, oncogenic herpesvirus. In Ethiopia, MD is believed to be introduced with importation of exotic and crossbred to improve the poultry production and has been reported to be a potential threat to the poultry sector both in backyard and commercial farming systems. This study was aimed at isolation and molecular analysis of MD virus isolates circulating in chicken population in the central part of Ethiopia where commercial farms are populated. From September 2013 to January 2014, clinical and post-mortem examination were conducted on diseased chickens suspected of MD virus infection. Representative spleen and feather follicle samples were collected following sterile procedure, and infectious virus isolation was performed using primary chicken fibroblast cell culture. Cell culture inoculated with suspension of pathological samples developed characteristic MD virus cytopathic effect of rounding of the cells and small plaques. Further analysis of the virus was conducted by conventional PCR amplifying the ICP4 gene fragment from eleven tissue samples using MD virus specific primers. PCR products were further sequenced and analyzed. Nucleotide sequence similarity search of the local isolates resulted a high degree of sequence similarity with Gallid Herpes virus type 2 strain (Marek’s disease virus type 1, JN034558). To our knowledge, the present study is the first report conducted on virus isolation and molecular characterization of MD virus isolates circulated in Ethiopia. Eleven ICP4-like gene fragment (318 bp) sequences generated in the present study were uploaded in the public database (KU842366–76). Further research on virus isolation, genetic characterization, and infection dynamics is recommended targeting chickens of all age groups reared in different agro-ecological zones under different production system.