Estimating Additive and Dominance Variance for Litter Traits in Purebred California White Kits Using Different Models

Reproductive and growth records of 82 purebred California white kits were used to estimate additive and dominance genetic variances using BULPF90PC-PACK. Estimates were obtained for litter size at birth (LSB) and at weaning (LSW); litter weight at birth (LWB) and at weaning (LWW); individual kit weight at birth (IKWB)and at weaning (IKWW)as well as neonatal (Nil) and morlality at weaning (WM). Two mixed model equations were adopted. The first model included fixed effects and random effects identifying inbreeding depression, additive gene effect and permanent environmental effects. The second model was similar to the first model, but included the dominance genotypic effect. Estimates of heritability from sire component of variance for LSB, LSW, LWB, LWW, IKWB and IKWW were 0.4810.53,0.41/0.44, 0.5010.55 ,0.491NA, 0.4410.47 and 0.48/0.56 from model 1 and 2 respectively. Proportions of dominance effect to total phenotypic variance from the dominance model were 0.222, 0.453, 0.206, 0.349, 0.417 and 0.521 for LSB, LSW, LWB, LWW, IKWB and IKWW respectively. Dominance effects, which are not transferable through gametes (haploid entities) but are recreated at random in the offspring, were found to influence the litter traits analyzed. Therefore, genetic evaluation with the dominance model (Model 2) was found more appropriate than the animal model (Model 1). Keywords: Additive, Dominance, Heritability, Inbreeding, Rabbi

Evaluation of fertility traits of Friesian X Bunaji dairy cows

Data from 13 primaparous and 47 multiparous Friesian-Bunaji (F1)  crossbred cows were used to evaluate the reproductive performance of Friesian x Bunaji dairy cows. Four fertility traits; days to first insemination (DFI), days open (DO), Non-return rate 56 days after first insemination (NRR56) and numbers of insemination per conception (NIC) were analysed . The results revealed that the average days to first insemination (DFI), days open (DO) , number of insemination per conception (NIC), and non- return rate 56 days after first insemination (NRR56) were 122.29 days, 171.18 days, 1.64, and 61%, respectively. These traits were highly variability (CV = 54.01-80.90%). The effects of sire and sex of calf on the reproductive characteristics were not significant (p>0.05). The dam body condition score (BCS) had significant effect on all the reproductive characteristics. The DFI, DO and NIC decreased with increase in BCS. Dams with BCS of < 2.50 had longer DFI and DO, and required higher numberof inseminations before conception (NIC), while those with BCS of >3.50 had shorter DFI and DO with minimum number of insemination per  conception (1.00). Dam parity had no significant effect (p>0.05) on the reproductive characteristics except on NRR56 and NIC. However, the heifer had longer days to first insemination (DFI), and days open (DO) andrequired higher number of inseminations per conception than the older cows. Season of calving had no significant effect (p>0.05) on the reproductive characteristics except on NRR56. The cows that calved during the wet seasons (early and late dry) had higher NRR56 (69 – 71%), than those of the dry (early and late wet) seasons (40 – 59%). The reproductiveperformance of the cows depreciated significantly (p<0.05) within the 3 years (2010 - 2012) of this study; DFI increased from 88.47 to 131.49 days, DO increased from 80.39 to 269.14 days, NIC increased from 1.01 to 2.72, while the percentage non-return rate (NRR56) decreased from 86% to 42%.The heritability (h2) estimates for fertility traits was very low ranging from 0.014 to 0.087. Dam body condition score, parity, season and year of calving are important sources of variation in fertility traits of dairy cows. These results illustrate that environmental effects makes larger contributions to the variability of fertility traits than direct genetic effects, thus reproductive health and feeding management are very importantdeterminant of reproductive performance of dairy cows.Keywords: Fertility, Friesian x Bunaji cows, Parity, Body condition score, Season, Yea

Genetic and Non Genetic Sources of Variation for Linear Body Conformation Traits in Bunaji and Friesian X Bunaji cows

The effects of Age of dam at calving, Sex of calf, Breed, Sire, month of calving and season of lactation on linear body conformation traits was investigated in the dairy herd of the National Animal Production Research Institute, Shika Zaria, Nigeria. Seven linear body conformation traits of 25 Bunaji and 25 crossbred (Friesian x Bunaji) cows were measured. The measurements were taken monthly by 3 evaluators for the complete lactation length of the cows, this resulted in 1275 cumulative records, (with 750 records from Friesian x Bunaji and 525 records from Bunaji). The 7 body conformation traits (stature, chest width, wither height, heart girth, body length, body depth and rump width) were measured in centimeter using flexible tape. The results showed that all the genetic and non genetic factors considered had significant effect (P<0.05) on the linear body conformation traits. However, there was no significant (P>0.05) variation amongst the evaluators in their measurements, except RW. The body size characteristics increased with age. The male bearing cows were relatively broader (CW, HG) and longer (BL) than the female bearing cows, though there was no significant difference (P>0.05) in their statures (ST) and the body depth (BD). The crossbred cows were taller (ST, HW) longer (BL), broader (CW, HG), but less deep (BD) than the pure Bunaji. The animals of season 1 were taller (ST, WH), deeper (BD) and longer (BL) than the others. However, animals of season 2 and 3 had similar body sizes (ST, CW, BD, WH, HG, BL and RW). It is therefore suggested that in selecting for body conformation these genetic and non genetic factors should be taken into consideration.Key words: Friesian x Bunaji, linear body conformation, evaluators, breed, sir

Genetic and Non-Genetic Factors Affecting Litter Size and Birth Weight of Rabbit in Minna, Niger State, Nigeria

. Genetic and non-genetic factors influencing litter size and birth weight of rabbit was evaluated using New Zealand White and Chinchilla breeds. Parameters measured were total number of kittens born per litter, number of litter born alive, live litter birth weight and average litter birth weight. Results of the experiment revealed that dam breed had no significant affect on total number of kittens born per litter, number of litter born alive and average litter birth weight while live litter birth weight were affected. Sire breed and month of birth did not significantly influenced all the parameters measured. Heritability estimates were low to moderate for all the traits (0.27 to 0.44), while repeatability estimates were observed to be low (0.17 to 0.26). No heritability and repeatability values were estimated for average litter birth weight of kittens due to negative genetic variance. Significant correlations were found between litter size traits and birth weight. Correlation between litter size traits and average litter birth weight, as well as live litter birth weight and average litter birth weight were observed to be non-significant

Relationship Between Gestation Length and Birth Weight in Nigerian Sheep and Their Crosses

Effect of genotype and birth weight on gestation length was evaluated using Nigerian breeds of sheep and their crosses. The study was carried out at the Sheep Project Unit of Small Ruminant Research Programme (SRRP) of National Animal Production Research Institute (NAPRI), Ahmadu Bello University, Shika-Zaria. The sheep breeds used were Balami, Uda and Yankasa. Heat (estrus) detection was carried out twice daily; in the morning (07:00-08:00 hours); and in the evening (16:00-17:00 hours) using apron fitted rams to pick does on heat. A total of 56 lambs were used for this study. The data obtained were subjected to analysis of variance using General Linear Model and Correlation Procedure of SAS. All the genotypes had similar gestation length with values between 150.3±0.61 days and 153.3±0.60 days, except for Balami pure breed (BAL X BAL) lambs that recorded a shorter gestation length (137.1±0.81 days). There was a wide variation in the birth weight of lambs with the crosses between Balami rams and Yankasa ewes recording a distinct birth weight of 3.5±0.08 kg while the crosses obtained using Yankasa rams on Uda and Balami ewes gave the lowest birth weights (1.7±0.19 and 1.4±0.18, respectively). Sex and litter type have no significant effect (P>0.05) on gestation length. Birth weight was however affected by sex of lambs and their litter type. Litter type was negatively correlated with birth weight (-0.372). Gestation length had a low and non-significant relationship with birth weight; litter type and lamb genotype. Lamb genotype does not have a significant relationship with litter type. Genetic improvement of Nigeria sheep breed is possible if the resources of within and between breed is exploited. Selection for a reduction in gestation length may indirectly increase prolificacy. (Animal Production 12(3): 135-138 (2010)Key Words : gestation length, birth weight, Nigerian Shee

Relationship Between Gestation Length and Birth Weight in Nigerian Sheep and Their Crosses

Effect of genotype and birth weight on gestation length was evaluated using Nigerian breeds of sheep and their crosses. The study was carried out at the Sheep Project Unit of Small Ruminant Research Programme (SRRP) of National Animal Production Research Institute (NAPRI), Ahmadu Bello University, Shika-Zaria. The sheep breeds used were Balami, Uda and Yankasa. Heat (estrus) detection was carried out twice daily; in the morning (07:00-08:00 hours); and in the evening (16:00-17:00 hours) using apron fitted rams to pick does on heat. A total of 56 lambs were used for this study. The data obtained were subjected to analysis of variance using General Linear Model and Correlation Procedure of SAS. All the genotypes had similar gestation length with values between 150.3±0.61 days and 153.3±0.60 days, except for Balami pure breed (BAL X BAL) lambs that recorded a shorter gestation length (137.1±0.81 days). There was a wide variation in the birth weight of lambs with the crosses between Balami rams and Yankasa ewes recording a distinct birth weight of 3.5±0.08 kg while the crosses obtained using Yankasa rams on Uda and Balami ewes gave the lowest birth weights (1.7±0.19 and 1.4±0.18, respectively). Sex and litter type have no significant effect (P>0.05) on gestation length. Birth weight was however affected by sex of lambs and their litter type. Litter type was negatively correlated with birth weight (-0.372). Gestation length had a low and non-significant relationship with birth weight; litter type and lamb genotype. Lamb genotype does not have a significant relationship with litter type. Genetic improvement of Nigeria sheep breed is possible if the resources of within and between breed is exploited. Selection for a reduction in gestation length may indirectly increase prolificacy. (Animal Production 12(3): 135-138 (2010

Fulani cattle productivity and management in the Kachia grazing reserve, Nigeria

Kachia Grazing Reserve (KGR) in northern Nigeria was home to some 10,000 Fulani pastoralists and their 40,000 cattle in June 2011. This study examines productivity and management of cattle belonging to livestock keepers within the reserve before and after a mass immigration event when 3,000 refugees moved into the reserve with their cattle to escape inter-community violence during May 2011. Data, on livestock management strategies (transhumance) and production parameters (herd size, composition, fertility, dynamics), were collected in March, June and October 2011.Cattle productivity in KGR is geared to supporting Fulani households while maintaining herd wealth. High offtake of young animals, especially the selling of heifers, was an unusual finding and may indicate that KGR pastoralists have been restricting their herd size voluntarily as well as limiting milk production to household requirements. This is probably due to the absence of a commercial milk market and a higher reliance on the sale of young stock to meet cash needs.Despite the widespread perception that grazing reserves are promoting sedentarisation of Fulani pastoralists and curbing transhumance, the inhabitants of the KGR were observed to practise wide-ranging transhumance both during wet and dry seasons driven by the limited availability of grazing. Some households selected a sub-sample of animals for transhumance rather than sending their whole herd, and some maintained cattle on alternative land-holdings outside the reserve. KGR households described modifying their usual transhumance practices in response to the mass immigration event and insecurity.Nevertheless, the herd demography results from this study are broadly similar to data obtained from other studies over the past 40 years, indicating that productivity and management practices have remained relatively unchanged

Repeatability of Objective Measurements of Linear Udder and Body Conformation Traits in Frisian X Bunaji Cows

The objective of this study was to estimates the repeatability of objective measurements on linear udder and body conformation traits and to evaluate the objectivity of the measurements in Friesian x Bunaji cows. Data from 50 (F1) Frisian X Bunaji cows collected between 2007 and 2008 at the Dairy Research Farm of the National Animal Production Research Institute (NAPRI), Shika, Zaria, Nigeria, were used for the study. Analyzed conformation traits were seven body conformation traits: stature (ST), chest width (CW), withers height (WH), heart girth (HG), body length (BL), body depth (BD) and rump width(RW) and seven udder conformation traits: rear udder height (RUH), rear udder width (RUW), udder depth (UD), udder cleft (UC), fore teat position (FTP), rear teat placements (RTP) and teat length (TL). Both were measured in centimeter (cm) using a flexible meter tape. Three novice evaluators participated in the experiment. The frequency of measurements was once a month, commencing 3-4 days post-partum. Each of the three evaluators was able to take 10 repeated records on each of the 50 cows within the lactation length, resulted in 1500 cumulative records. Number of lactations and evaluators were included in the model as fixed factors. The objectivity of the method, measured by repeatability among the three evaluators was satisfactory: 0.940, 0.873, 0.954, 0.892, 0.941, 0.955, 0.899 for the seven body conformation traits (ST, CW, BD, HW, HG, BL and RW, respectively), and 0.938, 0.935, 0.674, 0.829, 0.38, 0.847, 0.827, for the seven udder conformation traits (RUH, RUW, UC, RTP, FTP and TL, respectively). The variation due to evaluators’ effect was significant (p<0.01) on all the udder measurements except UC and TL, but not significant (p>0.05) on the body measurements except RW. Number of lactation had significant effect (p<0.01) on all the udder and body conformation traits except UC, ST, WH and BL. Although novices took the measurements, the objectivity of the method was satisfactory and sufficiently reliable to be used as an alternative method of evaluating linear udder and body conformation traits in dairy cows

The herd structure of breeding does of small holder Red Sokoto goat

A study to ascertain the heard structure of breeding does of small holder goat production system was conducted in Kano using 15 goat herds selected at random in 3 villages. A total of 250 breeding does were involved. The results indicate that parity of does in the observed herds ranged from one to ten. Twelve percent of the does within the age range, 5-25 months were yet to kid for the first time. In the herds, does that did not kid at least once, up to the age of 25 months were culled. However, majorities of the does were in their 2nd and 3rd parities and within the age range of 12-25 months. Twinning was common at 1st parity, irrespective of the age of does. Parity and litter size of does were the major determining factors on the observed herd structure for the breeding does. The observed structure indicates that <12 months does constitute 20% of the herd; 12- 25 months 48%; 26-39months 11.2% and; >40months 20.8%. Breeding does leave the herds starting from the 25th month of age at parity 2, 4, 7 and 10, respectively.Keywords: Herd structure, breeding does, Red Sokoto Goats