Managerial practices and factors influencing reproductive performance of dairy cows in urban/peri-urban areas of Kampala and Gulu,Uganda

Background

Urban/peri-urban dairy production and sales has evolved as an adjustment to cope with food security and economic needs for urban dwellers in low-income countries and created an opportunity to transform from subsistence rural lifestyles of dairy farming to commercial engagement in towns. However, urban/peri-urban dairy farms differ in challenges from rural dairy farms and reproduction is important and critical for assuring sustainable economic output in both environments. Here we recorded for the first time differences between two geographically and economically different cities corresponding to different settings within the same country in managerial factors influencing reproductive performance in urban/peri-urban dairy cowherds.

Results

The urban/peri-urban dairy farmers in the capital Kampala were more often male (P = 0.002) and commercialized (P = 0.0025), more experienced (P = 0.0001) and practiced zero-grazing more often (P = 0.05) than in the regional municipality Gulu. Also, the milk production per herd and cow (P = 0.0005) and calving rate were (P = 0.0001) higher in Kampala and artificial insemination was more commonly (P = 0.002) used than in Gulu. There was no difference in abortion nor neonatal mortality rate between the two locations. Overall, calving rates were higher (P = 0.0003) in smaller (≤3 dairy cows) and open grazing (P = 0.003) herds. Abortion rates were higher among dairy herds practicing late (≥5 months) (P = 0.003) calf weaning and in herds with commercial purposes (P = 0.0001). Neonatal calf mortality was lower (P = 0.01) in small herds.

Conclusion

The study showed significant differences between Kampala and Gulu in reproductive performance and related husbandry factors for cows in the urban/peri-urban dairy farming systems. For several reproductive performance traits we found associations with husbandry and production traits, which should be taken into account when providing advice to the urban and peri-urban dairy farmers in the tropics.     

A cross-sectional pilot study to estimate the prevalence of and risk factors for leptospirosis in South-Western Victorian dairy herds, 2017

Leptospirosis is a zoonosis, found worldwide, affecting many species of animals. We conducted a cross-sectional study to estimate the prevalence of Leptospira borgpetersenii sv Hardjo and Leptospira interrogans sv Pomona in cattle in dairy herds in South-Western Victoria, Australia. Fifty-three herds were enrolled in the study. Urine samples were collected from 15 late-lactation cows in each herd. A questionnaire was provided to herd managers at the time of each herd visit, asking them to describe the methods they used for controlling leptospirosis, including vaccination. Urine samples were pooled at the herd level and tested for leptospira spp. using real time PCR. Urine samples from individual cows within the positive pooled samples were then tested for Leptospira Hardjo and Leptospira Pomona using qPCR. Four of the 53 herds showed positive leptospirosis results giving an apparent prevalence of 8 (95% CI 2–18) leptospira-positive herds per 100 herds at risk. Based on the 53 completed questionnaires, leptospirosis vaccination programs were not compliant with label directions in 36 of the 52 vaccinated herds: 69 (95% CI 55–81) of 100 herd managers that routinely vaccinated for leptospirosis did not comply with label directions. One herd was completely unvaccinated. Based on our findings, we estimate that approximately 10% of dairy farms in South-Western Victoria are likely to be infected with leptospirosis. While most herds are vaccinating for leptospirosis, most are not doing so according to label directions. We conclude that herd managers need to be better educated regarding leptospirosis vaccination programs.     

Polymorphisms in genes of the somatotrophic axis are independently associated with milk production, udder health, survival and animal size in Holstein-Friesian dairy cattle

The somatotrophic axis consisting of pituitary-derived growth hormone and circulating insulin-like growth factor 1 has been well established as key regulators of animal health, metabolism, lactation, fertility, body composition and growth rate. The aim of this study was to simultaneously quantify the associations between SNPs in candidate genes of the somatotrophic axis (i.e., IGF-1, GH1 and GHR) with performance traits in Holstein-Friesian (HF) dairy cattle. Both novel SNPs identified previously by this group alongside other published SNPs within these genes were analysed for associations with performance in dairy cattle. Multiple regression analyses regressing genetic merit of up to 848 HF sires on novel SNPs (n = 76) and published SNPs (n = 33) were undertaken using weighted animal mixed linear models. Twenty-three SNPs were significantly associated with at least one of 18 traits analysed and involved in milk production, udder health, fertility and growth. Eight traits including milk fat composition, carcass conformation, stature, chest width, body depth, rump width, carcass and cull cow weight were independently associated with SNPs in two genes. Furthermore, for several traits including milk fat yield, somatic cell count, survival and carcass fat, SNPs in all three genes were independently associated with performance. Milk fat yield and carcass fat showed the highest number of independent associations across all three genes with five SNPs associated with both traits. The cumulative effects of the favourable alleles of all five SNPs across GH1, GHR and IGF-1 result in an increase of 5.9 kg and 28.6 units of milk fat and carcass fat, respectively. Cow survival was associated with a single SNP in each of the three genes with a cumulative allele effect of 1.5%. Independent effects of polymorphisms in GH1, GHR and IGF-1 reinforce the central role of the somatotrophic axis on animal development and performance.     

The effect of dietary supplementation with Aurantiochytrium limacinum on lactating dairy cows in terms of animal health,productivity and milk composition

The aim of this study was to investigate the effect of dietary supplementation with the docosahexaenoic acid (DHA )‐rich microalgae, Aurantiochytrium limacinum (AURA ), on a variety of health and productivity parameters in lactating cows. Twenty‐four cows were blocked by parity and number of days in milk and then randomly assigned to a control (CON ; n  = 12) group with no algal supplementation, or a treatment group (AURA ; n  = 12) provided with 100 g AURA  cow^?1 day^?1 or 16 g DHA  cow^?1 day^?1. A variety of health and productivity measurements were taken, and results indicated that supplementation had no negative effects on animal health in terms of somatic cell count, haematological and biochemical blood parameters, while body condition was marginally improved by algal supplementation. No differences were found for the various production parameters measured; however, a tendency towards increased milk production was observed for the AURA group during the final stage of the study (+4.5 kg cow^?1 day^?1, day 78–84). The fatty acid profile of milk was improved by supplementation, with significantly lower saturated fatty acids, significantly higher omega‐3 fatty acids and an improved omega‐3/omega‐6 ratio observed when compared to the control group. The amount of DHA in the milk of cows provided 105 g AURA  head^?1 day^?1 was 4.7 mg/100 g milk with a peak transfer efficiency from feed to milk at day 49 of 8.3%. These results indicate that supplementation with 105 g AURA  head^?1 day^?1 resulted in the successful enrichment of milk with DHA without negatively impacting the health or productivity of the animals.