Comparative assessment of economically valuable traits of semi-coarse hair and coarse-hair sheep in Republic of Tuva

In Republic of Tuva sheep breeding is a leading branch of animal husbandry. According to the Ministry of Agriculture and Food, the number of sheep is 980 thousand heads at the 1st of January 2021. Among them the percentage of Tuva-Saraja coarse-hair hybrids is more than 60%. The purpose of the work is to study economically valuable traits of Tuva-Saraja sheep of a new type in comparison with Tuva coarse-hair short-fat tailed sheep. For comparative assessment of live weight, dirty wool clip and length of wool according to the method of random sample, out of the herd there were selected 30 heads of ram lambs yearlings and 30 heads of ewe lambs yearlings of Tuva-Saraja semi-coarse-hair sheep of new type and Tuva coarse-hair short-fat tailed sheep. The results of research have shown, that rams and ewes yearlings of Tuva-Saraja semi-coarse-hair breed of new type significantly differ in size and wool productivity. They predominate over the lambs of the same age of Tuva coarse-hair short-fat tailed in live weight by 3.2-3.4 kg (9,7-10.2 %) statistically more, than Tuva coarse-hair short-fat tailed of the same age. The longest wool was recorded in rams yearlings of new type, with underwool of 7.8 cm that exceeded the length of underwool of Tuva ram lambs yearlings by 1.3 cm or 20.0 %, the top hair was 14.4 cm and exceeded the same index in analogues by 3,4 cm or 30.9 %. Tuva coarse-hair ewe lambs yearlings gave way to the semi-coarse-hair ewes of new type in the length of underwool and top hair. Thus, the rams and ewes yearlings semi-coarse-hair ewes of new type considerably differ in live weight, dirty wool clip and length of wool in comparison with Tuva coarse-hair short-fat tailed of the same age.

Administration of royal jelly in estrus synchronization protocols for wool and hair sheep

Objective: To assess the most relevant results on the usage of royal jelly in reproductive protocols of wool and hair sheep. Design/methodology/approach: A review of studies referenced and published in scientific databases regard the livestock sector. Results: In ewes, administration of “royal jelly” in addition to reproductive management protocols improves the response to estrus synchronization, time of onset and duration of estrus, number of large follicles, ovulatory rate and gestation rate. Study limitations/implications: Royal jelly is a substance with beneficial effects on reproductive variables in ewes; however, the cost may be a limitation for its incorporation in synchronization protocols. Additionally, it is necessary to clarify the active metabolites that exert the action and the most effective route of administration. Findings/conclusions: Royal jelly can be an alternative incorporated to estrus synchronization programs in ewes to substitute some hormones without decreasing reproductive variables.

PSXIV-19 Heritability for growth and resistance to gastrointestinal parasitism in meat goats and hair sheep

Genetic selection for resistance to internal parasitism is of great research interest. Heritabilities were determined for average daily gain (ADG), logarithmic transformed fecal egg count (FEC), packed cell volume (PCV), and serum immunoglobin (Ig) levels of growing male meat goats and hair sheep from different farms in the southcentral USA during three consecutive central performance tests (CPT). Tests entailed 7–10 wk of data collection after artificial infection with Haemonchus contortus. In year 1, animals evaluated were selected randomly and in years 2 and 3 progeny of CPT sires classified as highly or moderately resistant, which included 46, 50, and 51 Boer, Kiko, and Spanish and 59, 61, 34, and 46 Dorper, Katahdin-farm A, Katahdin-farm B, and St. Croix, respectively. Females were classified accordingly on-farm based on FEC and FAMACHA. Pedigree records consisted of 32 and 57 known sires, 95 and 152 known dams including 4 and 10 full-sibs and 97 and 149 half-sibs for goats and sheep, respectively. Variance components and heritabilities were estimated by AIREML using WOMBAT with a multivariate animal model. Heritability estimates were 0.48 ± 0.214 and 0.85 ± 0.157 of ADG, 0.31 ± 0.237 and 0.20 ± 0.172 of FEC, 0.60 ± 0.206 and 0.24 ± 0.185 of PCV, 0.26 ± 0.172 and 0.51 ± 0.167 of IgA, 0.335 and 0.543 of IgM, and 0.14 ± 0.192 and 0.31 ± 0.190 of IgG for goats and sheep, respectively. Reasons for relatively high heritabilities for all traits include the low residual variance estimates due primarily to a standardized environment in the performance test. In conclusion, moderate to high heritabilities were found for growth performance and response to parasite infection for growing meat goat and hair sheep males under a standardized environment that suggests considerable for genetic improvement through selection.

360 Body Temperature of Hair Sheep Ewes During the Postpartum Period and Around the Time of Mating in an Accelerated Lambing System in the Tropics

The study was conducted to evaluate body temperature of hair sheep ewes at various stages of the production cycle in an accelerated lambing system in the tropics. Multiparous St. Croix White (STX: n = 7) and Dorper x STX (DRPX; n = 7) ewes lambing in October and raising single lambs weaned at 120 d were used. Synchronized breeding began at 96 d postpartum. Vaginal temperature (VT) was measured at 10-min intervals for 96 h at 38 and 66 d post-partum (PP1, PP2) and at 2 days after mating (PM) using data loggers. Daily minimum, maximum and range of VT were determined for ewes within PP1, PP2 and PB. Data were analyzed using GLM procedures of SAS with breed, day and time (PP1, PP2, PM) in the model. Mean ambient temperature, temperature-humidity index and solar radiation at PP1, PP2 and PM were 24.8 °C, 25.2 °C, 23.8 °C, and 74.7, 74.9, 73.3, and 180 W/m2, 160 W/m2 and 155 W/m2, respectively. Minimum VT was lower (P < 0.002) in STX than DRPX ewes at PP1, PP2 but not PM (38.27 ± 0.04 vs 38.44 ± 0.04 °C, 38.16 ± 0.04 vs 38.33 ± 0.04 °C, 38.47 ± 0.04 vs 38.58 ± 0.04 °C, respectively). There was no difference in maximum VT between breed or time (P > 01.0). There was no breed difference (P > 0.10) in range of VT, but the range of VT was lower (P < 0.0001) at PM compared to PP1 and PP2 (1.22 ± 0.04 vs 1.77 ± 0.04 vs 1.63 ± 0.04 °C, respectively). These results show that tropically adapted STX ewes have lower body temperatures, as shown by the lower minimal VT which indicates a degree of nighttime cooling, during the postpartum period compared to DRPX ewes in a tropical environment.

PSXII-28 Effects of the nutritional plane before and after breeding on performance of different hair sheep breeds

Female hair sheep, 27 Dorper (DOR), 41 Katahdin (KAT), and 39 St. Croix (STC), were used to determine influences of nutritional planes before and after breeding on performance. There were 35 multiparous and 72 primiparous sheep, the latter 2.8±0.20 yr of age. Wheat straw [4% crude protein; dry matter (DM) basis] was consumed ad libitum and supplemented with approximately 0.25% initial body weight (BW) of soybean meal (SBM; Low) or a 1:3 mixture of SBM and rolled corn at 1% BW (High; DM). The supplementation period was 162 d, and with breeding of animals in 2 groups sequentially the pre-breeding period was 84 and 97 d and that after breeding began was 78 and 65 d. Wheat straw DM intake (1.75, 1.30, 1.57, 1.15, 1.80, and 1.38% BW; SEM=0.112), average daily gain (-46, 42, -44, 70, -47, and 51 g; SEM=7.3), and change in body condition score (-0.61, 0.36, -0.53, 0.27, -0.39, and -0.18 for DOR-Low, DOR-High, KAT-Low, KAT-High, STC-Low, and STC-High, respectively; SEM=0.058) were influenced (P < 0.05) by supplement treatment. Birth rate (66.7, 93.5, 84.6, 95.5, 82.8, and 100.0; SEM=9.83) and individual lamb birth weight (4.50, 4.61, 4.28, 3.98, 3.73, and 3.88 kg; SEM=0.201) were not affected by supplement treatment (P = 0.063 and 0.787, respectively), although litter size (0.92, 1.21, 1.17, 1.86, 1.12, and 1.82; SEM=0.221) and total litter birth weight (5.84, 5.74, 5.92, 7.52, 5.04, and 6.78 kg for DOR-Low, DOR-High, KAT-Low, KAT-High, STC-Low, and STC-High, respectively; SEM=0.529) were greater (P < 0.05) for High than for Low. In conclusion, although there was some compensation in wheat straw intake for the different levels of supplementation, SBM given alone rather than with cereal grain adversely affected body weight and condition and reproductive performance, the latter primarily through litter size but also via a trend for an effect on birth rate.

PSXIV-18 Genetic improvement for resistance to gastrointestinal parasitism in growing meat goats and hair sheep through a centralized performance test in the southcentral USA

Progress from selecting meat goats and hair sheep from different farms in the southcentral United States for resistance to internal parasitism during three consecutive central performance tests was evaluated. Tests entailed 7–10 wk of data collection after artificial infection of growing males with Haemonchus contortus larvae. There were 44, 50, and 50 Boer, Kiko, and Spanish goats and 54, 55, 34, and 47 Dorper, Katahdin-farm-A, Katahdin-farm-B, and St. Croix sheep, respectively. In year 1, males were randomly selected and in years 2 and 3 were progeny of sires and females classified as highly and moderately resistant. Criteria for males was average daily gain and residual feed intake during the performance test and means of fecal egg count (FEC) and packed cell volume after artificial infection and for females was FEC and FAMACHA on-farm. There were interactions in FEC of breed×year (P < 0.001) for both species (1,046; 1,134; and 2,630 for Boer; 3,781; 1,239; and 1,216 for Kiko; 1,303; 1,357; and 1,464 for Spanish; 3,288; 1,956; and 1,315 for Dorper; 1,528; 1,759; and 2,241 for Katahdin-A, 2,414; 3,874; and 1,793 for Katahdin-B; and 1,371; 1,160; and 1,175 eggs/g for St. Croix in years 1, 2, and 3, respectively) and year×resistance group (RG; P = 0.005) for goats (1,359; 610, and 552 for high; 1,951; 1,268; and 1,440 for moderate; 2,821; 1,852; and 3,118 eggs/g for low RG in years 1, 2, and 3, respectively) but not for sheep (P = 0.639). In conclusion, resistance appeared greatest for Spanish and St. Croix within species and was increased by selection of Kiko and Dorper. For highly resistant goats, lower FEC in year 2 and 3 vs. 1, compared with no year differences for moderate and low RG, indicates selection progress, and the lack of similar differences for sheep may reflect their relatively greater resistance.

PSXII-30 Genetic and phenotypic correlations for growth and resistance to gastrointestinal parasitism in meat goats and hair sheep

Genetic and phenotypic correlations for growth and response to parasite infection traits were estimated for growing male meat goats and hair sheep from different farms in the southcentral United States during three consecutive central performance tests (CPT). Data were collected for 7–10 wk after artificial infection with Haemonchus contortus, which included average daily gain (ADG), fecal egg count (FEC), packed cell volume (PCV), and immunoglobin (Ig) levels. Animals evaluated were selected randomly in year 1 and in years 2 and 3 progeny of CPT sires classified as highly or moderately resistant and included 46, 50, and 51 Boer, Kiko, and Spanish goats and 59, 61, 34, and 46 Dorper, Katahdin-farm A, Katahdin-farm B, and St. Croix sheep, respectively. Females were classified accordingly on-farm based on FEC and FAMACHA. Pedigree records included 4 and 10 full-sibs and 97 and 149 half-sibs for goats and sheep, respectively. Variance components and correlations were estimated by AIREML using WOMBAT with a multivariate animal model. The additive genetic correlation between FEC and PCV was negative for goats (r=-041, P < 0.001) but positive for sheep (r=0.21, P = 0.004), whereas the phenotypic correlation between FEC and PCV was nonsignificant for goats but negative for sheep (r=-0.252, P < 0.001). The genetic correlation between FEC and IgA was positive (r=0.39, P < 0.001) for goats but nonsignificant (P = 0.439) for sheep, whereas those of FEC with IgM and IgG were both negative (r=-0.369 and -0.732 with IgM and r=-0.284 and -0.702 for goats and sheep, respectively; P < 0.001). Genetic and phenotypic correlations between ADG and FEC were nonsignificant for both species. In conclusion, different relationships of FEC and PCV between species require careful attention during selection and the lack of relationship between ADG and FEC suggests that selection of growing male meat goats and hair sheep for resistance to internal parasitism will not adversely affect growth performance.