Sex Of Lamb Research Articles

Some Reproductive Characteristics of Hasak and Hasmer Sheep: 1. Some Fertility Criteria

In this study, Hasak and Hasmer ewes were used in order to determine the effects of age, year and breed on the conception rate, prolificacy, viability and productivity. The least-squares means for these parameters of all flock were found as follows; 87.27±0.01 %, 117.16±0.01 %, 87.06±0.01 % and 103.34±0.02 %, respectively. In addition, the effects of sex of lamb and birth type on viability were also studied. Except for prolificacy, effects of the age on these parameters were found to be not statistically significant. The maximum prolificacy was obtained with 6-years old ewes. Effect of breed was significant on the prolificacy (P<0.05) and conception rate (P<0.01). With regard to prolificacy, Hasmer ewes were superior to Hasak (120.90 % vs. 113.41 %). The year factor had a significant effect only on the prolificacy (P<0.05). Birth type on the viability was not significant, but sex effect effected viability significantly; female lambs being superior to male ones.

Genetic and non-genetic analysis of lamb survival in Sangsari sheep by gibbs sampling method

The aim of this study was to investigate the genetic and non-genetic effects on survival traits of Sangsari sheep from birth to the last recording date. Data base with 35,470 sheep survival records was collected during 1988 to 2010 in 11 flocks by the Animal Breeding Center of Iran. The non-genetic effects were evaluated on hazard rate of sheep in different times with survival and cmprsk packages. Exponential distribution based on censored data was used to estimate the genetic parameters of the survival from birth to the last recording date. The linear animal models were fitted using Bayesian method via Gibbs sampling of the MCMCglmm package. The overall mortality rate for Sangsari lambs was 2.00 and 25.72% for birth to 100 and 500 day of age, respectively, and its value increased upto 90.54% till 3400 day of age. The results indicated that the year and month of birth, sex of lamb, birth weight, age of ewe, flock (P < 0.001), and type of birth (P < 0.01) had a significant effect on sheep survival. Estimated direct heritability for survival from birth to the last recording date by different linear models ranged 0.097 to 0.157. The contribution of maternal permanent environmental variance ratio was estimated higher than maternal heritability, thus this effect must be considered in the evaluation models for improving sheep survival. The present findings suggest that sheep survival improvement could be possible through management practice as well as genetic selection.

Predicting breeding value of body weight at 6-month age using Artificial Neural Networks in Kermani sheep breed

The present study aimed to apply artificial neural networks to predict the breeding values of body weight in 6-month age of Kermani sheep. For this purpose, records of 867 lambs including lamb sex, dam age, birth weight, weaning weight, age at 3-month (3 months old), age at 6-month (6 months old) and body weight at 3 months of age were used. Firstly, genetic parameters of the animals were estimated using ASReml software. The data was then pre-processed for using in MATLAB software. After initial experiments on the appropriate neural network architecture for body weight at 6-month age, two networks were examined. A feed-forward backpropagation multilayer perceptron (MLP) algorithm was used and 70% of all data used as training data, 15% as testing data and 15% as validating data, to prevent over-fitting of the artificial neural network. Results showed that the both networks capable to predict breeding values for body weight at 6 month-age in Kermani sheep. It can be concluded that artificial neural network has a good ability to predict growth traits in Kermani sheep with an acceptable speed and accuracy. Therefore, this network, instead of commonly-used procedures can be used to estimate the breeding values for productive and reproductive traits in domestic animals.

Pregnancy and Litter Size, But Not Lamb Sex, Affect Feed Intake and Wool Production by Merino-Type Ewes.

Simple SummaryWe examined whether feed intake and wool production are affected by pregnancy, litter size, or lamb sex on Merino genotype ewes. We observed that feed intake was influenced during pregnancy and lactation by litter size; whereas, wool production was influenced by litter size, but not by the sex of the lambs during pregnancy.Two experiments (Australia and Mexico) tested whether feed intake (FI) and wool production (WP) are affected by pregnancy (PRG), litter size (LZ), or lamb sex (LS) in Merino-type ewes. In Experiment-1, ewes were either not pregnant (NPR; n = 6), or carrying 1 (PR1; n = 7) or 3 (PR3; n = 11) fetuses, were studied in individual pens. NPR ewes had lower (p < 0.02) FI throughout PRG and lactation (LAC), except around lambing (p < 0.001). Following lambing, FI increased in PRG ewes (p < 0.001) to double the values in NPR ewes. PRG reduced WP (p < 0.001); in PR3, WP was lower than for both PR1 and NPR (p < 0.001). WP decreased during LAC and was lower in ewes rearing lambs than in NPR ewes (p < 0.001). Experiment-2 used 48 pregnant ewes (28 bearing singles and 20 bearing twins). Dam and lamb live weights (LW) and body condition (BC) were recorded from birth to weaning at 60 d, and dam fleece weight (DFW) was measured at weaning (12 months growth). WP was higher in ewes bearing and rearing single lambs than in ewes bearing twins (p < 0.001). DFW was positively (p < 0.01) related to LZ, dam LW, and BC, but not to changes in dam LW during LAC, or to lamb weight at birth or weaning, or LW gain, or LS. In conclusion, FI was affected during PRG and by LZ during LAC, whereas WP was influenced by LZ, but not LS, only during pregnancy.

Associations between lamb growth to weaning and dam udder and teat scores

ABSTRACTAims: To investigate associations between lamb growth to weaning and dam udder and teat scores measured at pre-mating, pre-lambing, docking and weaning.Methods: Mature Romney ewes (n = 1,009) were enrolled from a commercial sheep flock located near Masterton, in the Wellington region of New Zealand in 2017. A range of udder and teat traits were scored in all ewes, using visual assessment and palpation, at pre-mating, pre-lambing, docking and weaning. During the lambing period, each newborn lamb was matched to its dam and lamb sex, birthweight and birth-rank were recorded. A rearing rank was allocated to each live-lamb at weaning, when all lambs were weighed (n = 1,570), allowing calculation of daily growth rates (g/day). Associations between udder and teat scores and lamb growth rates to weaning were examined using multivariable models for each udder-scoring time.Results: Growth rates of lambs whose dams had udder palpation scores of hard, or both teats recorded as abnormal, pre-mating were lower than lambs whose dams had normal scores (229.9 (95% CI = 213.2–246.6) vs. 254.5 (95% CI = 245.6–263.5) g/day; p = 0.011) and (227.4 (95% CI = 208.3–246.6) vs. 247.9 (95% CI = 235.7–260.2) g/day; p = 0.024), respectively. Growth rates of lambs whose dams had clinical mastitis at docking or weaning were lower than those without mastitis (215.8 (95% CI = 199.9–231.7) vs. 235.4 (95% CI = 225.4–255.0) g/day; p = 0.007) and (220.0 (95% CI = 205.2–234.8) vs. 254.7 (95% CI = 248.9–260.5) g/day; p < 0.001), respectively. Growth rates of lambs whose dams had asymmetrical udders at docking or weaning were lower than lambs whose dams had symmetrical udders (204.6 (95% CI = 189.7–219.5) vs. 240.2 (95% CI = 225.4–255.0) g/day; p < 0.001) and (223.3 (95% CI = 213.9–232.7) vs. 242.2 (95% CI = 229.4–255.0) g/day; p = 0.014), respectively.Conclusions and Clinical Relevance: Pre-mating udder palpation and teat palpation scores can be used to identify ewes whose lambs are predicted to have lower growth to weaning. Assuming a mean lamb age at weaning of 84.4 days, lambs born to ewes with a pre-mating score of hard would be expected to have a mean weaning weight that was 2.1 kg less than those whose dams had normal scores. Udder palpation, udder symmetry and clinical mastitis scores during lactation were also associated with lamb growth rates.Abbreviation: CALW: Conceptus-adjusted liveweight

Study of the Weights and Dimensions of the Body in the Iraqi Awassi Sheep

This study was undertaken at the native feilds of the sheep farms in Sadet Al-hindia, Babylon Governorate, over period from December 2017 to March 2018. The aim of this was study the effect of type of birth and sex of lambs on the traits of birth and weaning weight, body dimensions(body length, chest circumference, height at the front and back)in awassi sheep. the results showed that significant superiority (p˂0.05) for twins lambs (40.9cm) on single lambs(39.33cm) in body length at the birth .for the sex of lambs, male lambs has significant superiority (p˂0.05) on female lambs in heightin front (41.03,40.07 cm Respectevly), but the type of birth and sex of lambs had nonsignificant effect of other parameters .

The Effects of Some Environmental Factors on Birth Weight and Estimation of Heritability and Repeatability for Birth Weight of Akkaraman Sheep in Konya Province

In this research, the effects of dam age and type of birth and sex of lambs on birth weight of Akkaraman lambs was investigated at village conditions in Konya province. Additionally, the heritability and repeatability of birth weight was estimated. The Least-squares means of birth weight was 4.07±0.04 kg. The effects of dam age, year, birth type and sex on birth weight were found statistically significant. The heritability and repeatability of birth weight were found as 0.052±0.04 and 0.130±0.04, respectively.

Effects of some medical and aromatic plant seeds on growth performance, milk yield and its composition of Rahmani and Chios sheep

The study was carried out to evaluate the effect of dried mixture of four herbal plant seeds as feed additives and some environmental factors on growth performance, milk yield and its composition of Rahmani and Chios sheep. Fifty four pregnant Rahmani and Chios ewes, during the last periods of pregnancy were divided into 3 groups (8 Rahmani and 10 Chios ewes each) using complete random block design. Group2 (G2) and group3 (G3) were supplemented with polyherbal combination at the rate of 3 and 6 g/100kg-1 LBW, respectively. Ewes without polyherbal combination served as a control (CTR). Body weight and ADG of G2 lambs was significantly (P<0.05) higher than G1 and control. Variations among genetic groups regarding body weights, TG and ADG were highly significant (P<0.01). Male lambs were significantly heavier (P<0.05 or P<0.01) than female except at birth, male lambs have attained TG heavier (P<0.01) than female lambs. There was a significant (P<0.01) effect of medical and aromatic plant seeds on colostrum yield at birth, 12, 24 and 36 hours, TMY and ADMY was affected significantly. There were significant difference between the two breeds in the production of milk per week, TMY and ADMY. Sex of lambs had a significant (p<0.05) effect on milk produced at the 2nd, 6th, 7th, 8th and 9th weeks of lactation. TMY and ADMY was affected significantly by sex of lambs. TMY and ADMY was (P<0.01) greater in ewes rearing twin lambs compared with ewes rearing singles. Colostrum fat and energy was affected (P<0.05) by treatments. As well as, milk components except lactose are (P<0.01) affected. Colostrum ingredient, except TS were not significantly affected by breed of ewes. TS level significantly increased in colostrum of Chios than Rahmani ewes. The ewe breed had a significant (P<0.01) effect on fat, TS, ash, SNF and milk energy. All colostrum components were not significantly affected by age of ewes. But, TS, ash and energy of milk were affected (P<0.01) by age of ewes. Milk constituents were affected significantly (P<0.01) by different lactation stages. The results of this study indicated that the inclusion of some medical and aromatic plant seeds as feed additives in Rahmani and Chios diet improves growth performance, feed intake and milk yield.

Study of some physical wool characterization in Arabi ewes in Erbil Governorate

This study was carried out at Private flock in Murtkah District - Erbil Governorate. Samples of wool were taken from mid-side of 72 Arabi ewes during May, 2017. to study the effect of ewes age and the sex of the lambs on the physical wool characteristics The overall means of raw fleece weight, clean fleece, fiber diameter, crimps, staple length and fiber length were 1653.75 g, 79.06%, 28.24 micron, 1.33 cm, 9.36 cm and 16.03 cm respectively. The percentages of the fibers of each of Fine, Coarse and Kemp were 52.42, 38.89 and 8.68% respectively. and S/P ratio 1.27. Age of ewe effects appeared to be significant on raw fleece weight and coarse fiber (p ≤ 0.05), also on fine fiber and (S/P) ratio (p ≤ 0.01) only, while the effects of sex of lamb were non-significant on all physical wool properties except the percentage of kemp fiber (p ≤ 0.05). Although the maximum R-square increased very little gradually in the equation to predict fleece weight depending on body weight and dimensions, the simplest equation includes body weight could be considered the most significant (P<0.01) and more reliable than others to predict fleece weight (The equation is: fleece weight = 353.41 + 31.84 (body weight). The multiple regression equations were calculated to predict clean wool percentage, staple length, fiber length, crimps, fine fiber percentage, coarse fiber percentage, and S/P ratio from fleece weight, body weight and dimensions and the maximum R-square for all characteristics were very small. Fiber diameter could be predicted using the formula of multiple regression includes body weight and length and chest depth according to the maximum R-square (P<0.01). While Kemp fiber percentage could be predicted using the formula includes body weight, fleece weight and Shoulder height. Only the simple regression equation of Fleece weight on body weight was significant (P<0.01) with R-square (0.19). The correlation coefficient was done among all studied characteristics and ranged between -0.69 (p<0.01) (between fine fiber and coarse fibers) and 0.94 (p<0.01) (between fine fiber and S/P ratio). It was concluded that wool properties of Arabi sheep were not at standard level especially in both fine and Kemp properties and need to be improved

Direct and maternal variance components and genetic parameters for average daily body weight gain and Kleiber ratios in Nellore sheep.

The objective of the present study was to estimate variance components and genetic parameters for average daily gain from birth to weaning (ADGa), birth to 6months (ADGb) and 3 to 6months (ADGc) and corresponding Kleiber ratios (Ka, Kb, and Kc) in Nellore sheep. Data were collected from the records maintained at Livestock Research Station, Palamaner, for analysis and the data spread from 1993 to 2016 (23years). Lambing year, sex of lamb, season of lambing, and parity of dam were included in the model as fixed effects, and ewe weight was kept as a covariate. Six animal models were fitted with various combinations of direct and maternal genetic effects using restricted maximum likelihood procedure. The Akaike's information criterion was employed to determine the best model for each trait. Direct heritability estimates obtained in the study for ADGa, ADGb, ADGc, Ka, Kb, and Kc were 0.37, 0.41, 0.34, 0.48, 0.46, and 0.37, respectively, and their corresponding maternal heritabilities ranged from 0.11, 0.21, 0.11, 0.24, 0.22, and 0.11, respectively. (Co)variance among the direct and maternal effects were found to be negative in all the traits. Direct genetic correlations among the studied traits were positive with few exceptions, and they ranged from - 0.03 (Ka-Kc) to 0.99 (ADGa-Ka); similarly, the phenotypic correlations ranged from low to high - 0.18 (ADGa-Kc and Ka-Kc) to 0.95 (ADGa-Ka). These results indicated the importance of maternal effects in affecting the growth rate and efficiency of feed utilization traits and also suggested the possibility of moderate genetic progress for these traits through selection.

Effect of energy source and level, and animal age and sex on meat characteristics of sheep

Trial 1 was designed to identify meat quality differences due to sheep age (n = 16 ewe lambs, n = 16 yearling ewes, and n = 16 mature ewes) and diet (ad libitum alfalfa pellets (AP), and ad libitum whole shelled corn (WSC100)). Mature ewes had greater (P ≤ 0.02) lean CIELAB a* values when compared with yearling ewes and ewe lambs. Offering WSC100 resulted in a greater (P ≤ 0.05) CIELAB a* value from the fat of sheep carcasses. Longissimus thoracis (LT) cook loss and slice shear force (SSF) values decreased (P ≤ 0.01) with postmortem aging from 1 d to 14 d. Trial 2 was designed to identify meat quality differences due to diet (AP, WSC100, and 85% restricted intake of WSC; WSC85), lamb sex (n = 48 ewes and n = 48 wethers), and lamb age (n = 48 short-fed and n = 48 long-fed). Short-fed lambs had greater LT ultimate pH (P ≤ 0.05) and lean CIELAB L* values (P ≤ 0.01) when compared with long-fed lambs. Long-fed lambs had greater (P ≤ 0.05) CIELAB L* values from the fat of the carcass when compared with short-fed lambs. Lambs offered WSC100 produced carcass fat with greater (P ≤ 0.03) CIELAB a* values when compared with lambs offered AP. Long-fed lambs had a greater percentage of lipid in the LT (P ≤ 0.01) and the whole, boneless ground shoulder (P ≤ 0.01) and greater shoulder patty cook loss (P ≤ 0.01) when compared with samples from shorter-fed lambs. Offering WSC100 resulted in a greater (P ≤ 0.01) percentage of lipid in the shoulder patty when compared with offering AP and WSC85. Percent cook loss and SSF values decreased (P ≤ 0.05) in the LT when aged for 14 days when compared with 1 day. Across the two trials, indicators of sheep meat quality were not largely influenced by diet, age of the sheep, or sex of the sheep.

Regression Tree Approach for Assessing the Effects of Non-Genetic Factors on Birth Weight of Hemşin Lamb

This study examined effects of birth year, herd type, age of dam, lamb sex, birth type and lamb color on birth weight in Hemsin lambs using the regression tree method. The study used the data obtained from 9113 Hemsin lambs born between 2007-2010. The average birth weight of Hemsin lambs was found to be 3.55 kg and the standard deviation was 0.727 kg. Significant differences were found in birth weights of Hemsin lambs according to birth year (P&amp;lt;0.001), birth type (P&amp;lt;0.001) and lamb sec (P&amp;lt;0.01), whereas no statistically significant difference was found according to herd type, age of dam and lamb color (P&amp;gt;0.05). According to the regression tree diagram, the most important factors affecting birth weight of Hemsin lambs were birth year, birth type, sex, herd type and age of dam. The absence of lamb color in the regression tree diagram indicates its insignificant effect on birth weight. The low risk value (0.456) and high R-Squared value (0.862) of the regression tree model shows that the model is sufficient to explain birth weight. Variables of birth year, birth type, sex, herd type and age of dam explained 86.2% of the variation in birth weight.

Crecimiento pre y postdestete de corderos Pelibuey en clima cálido húmedo

Introducción: En México, existe una demanda insatisfecha de carne de ovino, para subsanarla, es necesario estudiar los sistemas de producción y determinar los factores que los afectan. Los objetivos de este estudio fueron evaluar el efecto año de nacimiento (AN), tipo de nacimiento (TN), época de nacimiento (EN), sexo del cordero (SX) y número de parto (NP) sobre características de crecimiento pre y postdestete de corderos Pelibuey y 2) estimar la relación entre las características de crecimiento pre y postdestete.Método: El estudio fue retrospectivo observacional con información productiva de una finca ovina localizada en el estado de Tabasco, México. El conjunto de datos provino de los registros productivos de 389 ovejas Pelibuey, correspondientes a 941 corderos de 629 partos. El modelo estadístico incluyó los efectos fijos de AN (2005 a 2008), TN (únicos y múltiples), EN (sequía, lluvias y nortes), NP (primíparas y multíparas) y SX (hembra y macho), y como efectos aleatorios madre dentro de AN y el error experimental. Se calcularon los coeficientes parciales de correlación de Pearson para todas las variables de respuesta. Las variables dependientes predestete fueron: peso al nacimiento (Pn), ganancia diaria de peso predestete ajustada a 60 d (Gan1) y peso al destete ajustado a 60 d de edad (Pda). Las variables dependientes postdestete fueron: ganancia diaria de peso postdestete ajustada (Gan2) y peso final ajustado a 106 d (Pfa). El peso final corresponde al último peso registrado en los registros productivos, tomado a una edad promedio de 165±49 d.Resultados: Con excepción de TN y EN sobre ganancia diaria de peso postdestete ajustada a 106 d (Gan2) y peso final ajustado a 106 d postdestete (Pfa), todas las variables explicativas afectaron (P≤0.05) las variables de respuesta predestete. El TN y EN afectaron el comportamiento predestete de los corderos (P&lt;0.01). Los corderos de nacimiento único presentaron mayores Pn, Gan1 y Pda (P&lt;0.01) comparado con corderos de nacimiento múltiple. Los corderos nacidos en lluvias y nortes tuvieron el mayor Pn (P≤0.05), los nacidos en sequía y lluvias tuvieron mayor Gan1 y los nacidos en sequía mayor Pda (P&lt;0.01) con respecto a las otras EN. Los corderos machos mostraron mayor Pn, Pda, Gan1, Pfa y Gan2 respecto a las hembras (P≤0.05). Corderos de madres multíparas tuvieron mejor comportamiento de crecimiento en todas las variables estudiadas respecto a los de primíparas (P&lt;0.01) con excepción de Gan2 (P&gt;0.05). Los coeficientes de correlación mas altos (P&lt;0.01) fueron observados entre Gan1 con Pda y Gan2 con Pfa. Los coeficientes de correlación variaron de 0.27 a 0.88 entre las variables dependientes estudiadas (P&lt;0.01).Conclusión: El AN afectó todas las variables predestete y postdestete. Sin embargo, no se detectó un año en donde todas las variables pre o postdestete fueran superiores o inferiores a la de otros AN. Los corderos únicos tuvieron mejor comportamiento productivo predestete que los múltiples. En la época de sequía el Pn de los corderos fue menor con respecto a las otras épocas. En nortes, los corderos tuvieron menor Gan1 y Pda comparado con las otras épocas. Los corderos machos fueron superiores en su comportamiento productivo predestete con respecto a las hembras. Los corderos provenientes de ovejas multíparas presentaron mejor eficiencia productiva predestete. En el comportamiento postdestete, Gan2 y Pfa no fueron afectados por el TN y EN. Gan2 fue afectada por NP. El Pn, Gan1 y Pda tuvieron una relación positiva con el Pfa.

Effects of Some Factors on Reproduction Performance of Akkaraman Sheep in Breeder Flocks in Konya Province, Turkey

In this study, 1408 Akkaraman ewes were used in order to determine the effects of age and year on the conception rate, prolificacy, productivity and viability. The least-squares means for these parameters of all flock were found as follows; 91.27±0.11 %, 135±0.30 %, 86.38±0.01 % and 94.63±0.01 %, respectively. In addition, the effects of sex of lamb and birth type on viability were also studied. Except for viability, effects of the age on these parameters were found to be statistically significant (P<0.01). The maximum productivity was obtained with 2-years old ewes. The year factor had a significant effect on all parameters (P<0.01 and P<0.05). Sex and birth type effects on the viability were not statistically significant.

Estimates of covariance functions for growth of Kordi sheep in Iran using random regression models

In the current paper, restricted maximum likelihood estimates of covariance functions for growth records from birth to 360 days of age in Kordi sheep population were estimated using random regression models (RRM). Kordi sheep is an important breed known for adaptability and resistance to unfavorable climatic conditions and suitable feed efficiency in mountainous regions of Iran. Data included 23,720 body weight records of 6730 Kordi lambs collected from 1989 to 2012 at Hossein Abad Kordi sheep Breeding Station in Shirvan city, North Khorasan province, Iran. Fixed effects in the model were lamb sex, birth type, and birth year as well as dam age. Legendre polynomials (LP) of order 3 was used for age to illustrate the average growth curve. In the random part, the functions with different orders were included to model variances associated to direct and maternal effects. Results showed that a model with LP of order 4,3,4,3 for direct additive genetic effects, animal permanent environmental effects, maternal additive genetic and maternal permanent environmental effects was sufficient to model changes in (co)variances with age, according to Akaike’s Information Criterion (AIC) and Bayesian information criterion (BIC). Direct additive genetic and animal permanent environment variances increased with age. Direct heritability (h2a) increased with age from 0.133 ± 0.021 at birth to 0.391 ± 0.034 at 360 days of age. The ratio of animal permanent environmental variances to phenotypic variance (pe2) was 0.047 ± 0.083 at birth, increased with age and reached 0.537 ± 0.034 at the end of the growth trajectory. Maternal heritability (h2m) was 0.152 ± 0.025 at birth decreased to 0.067 ± 0.016 until weaning and then fluctuated between 0.06 and 0.10. The ratio of maternal permanent environmental variances to phenotypic variance (mpe2) was 0.082 ± 0.02 at birth; however, it gradually decreased until the end of trajectory. The first eigenvalues of the coefficient matrices explained 69% and 91% of the total direct additive variance and maternal genetic variance, respectively. Direct genetic correlations ranged from low and negative to positively high, and generally decreased as the distance between tests increased. Current study has demonstrated that RRM have potential for modeling growth of Kordi sheep and a greater response to selection would be expected, if selection focuses on body weights from 30 days of age to 120 days of age.

Factors affecting differences between birth weight of littermates (BWTD) and the effects of BWTD on lamb performance

The objectives of this study were to determine factors affecting lamb birth weight (BWT) and differences between BWT of the largest and smallest littermates (BWTD) and to assess the relative importance of BWT and BWTD on lamb survival and growth to weaning. Records from twin (n = 5369) or triplet (n = 1664) litters born on pasture were utilised. Breeds included Coopworth, Romney, Perendale, composite and Texel. Ewe and sire breed, age and weight of the dam, sex, and number of lambs born (NLB) affected BWT. Neither embryo loss nor ovulation pattern (i.e. all ova released from one ovary or some from each) were associated with BWT. Dam weight and NLB affected BWTD but dam age, sire or dam breed did not. Loss of an embryo reduced BWTD, and BWTD was lower when the ewe ovulated from both ovaries versus only one ovary for twins, but not triplets. Whereas BWT was moderately heritable (h2 = 0.20), BWTD was not heritable (h2 = 0.003). Lamb survival was positively associated with BWT. Lambs with BWTD > 1.3 kg were less likely to survive (73.3%) than those from litters of smaller BWTD (range 82.8–85.7% survival). Growth rate of twin and triplet lambs was positively associated with BWT. Surprisingly, lambs from litters with moderately high BWTD had slightly greater (approximately 3%) growth rate than those from lambs of low to intermediate BWTD. Thus, while large BWTD were negatively associated with survival, BWT itself, which was moderately heritable, appeared to be a stronger driver of lamb survival and average daily gain.

Milk production and milk composition of the Boutsko bred of ewes in Epirus

A flock of 244 hill sheep of the indigenous Boutsko breed of Epirus (NW of Greece), 1-6 years old, reared under a transhumance system was used to study their milk productivity for a period of 14 months (March - June of next year). In addition three groups of ewes, aged 3 to 4 years (group A with 10 ewes suckling a single male lamb, group Βwith 10 ewes suckling a single female lamb and group C with 10 ewes suckling twin lambs) were kept under the same conditions of nutrition and management with the rest of the above flock. They were studied for a 26-week lactation period (4-week suckling period. 22-week milking period) to assess the effect of sex and number of lambs suckled on milk yield, milk composition and body reserves. The results of the study have been summarized as follows: 1) Lactation period (suckling period=4 weeks, milking period=32 weeks) was very long (36 weeks). Throughout milking period milk production of the ewes was 93.7 Kg. Of this 82.3% was produced during the winter period and 17.7% during the summer period. Persistency of milk production was low. One month after weaning of lambs the milk yield of ewes was reduced by 49% and 44% of the level at weaning for singlesuckled and twin-suckled ewes, respectively. 2) Throughout lactation, milk yield and milk composition were not affected by sex of lambs suckled. However, milk yield of ewes was affected by the number of suckled lambs; twin-suckled ewes produced more milk during the suckling period ( + 15.7%, Ρ &lt; 0.05) and milking period (+21.8%, Ρ &lt; 0.05) than those of single-suckled ewes. Fat, protein and dry matter concentration of milk was lower (P&lt;0.05) in twin-suckled ewes than in single-suckled ewes. Concentration of all milk constituents was affected by stage of lactation (P&lt;0.05).

Heritability estimates for average daily gain and kleiber ratio in deccani sheep

To study the factors affecting average daily gain (ADG) and Kleiber ratio (KR) and to estimate the heritability for these traits, data of 1294 Deccani lambs maintained at ICAR-Network Project on Sheep Improvement, MPKV, Rahuri (Maharashtra) were used. The least-squares means for ADG1 (birth to weaning) and ADG 2 (weaning to six months of age) were 123.28±0.82 and 83.17±1.07 g, respectively. The least-squares means for KR 1 (ADG 1/weaning weight0.75) and KR 2 (ADG 2/six month weight0.75) were 16.47±0.05 and 8.02±0.09, respectively. Year and season of birth, sex of lamb and ewe's weight at lambing had significant (P<0.01) influence on ADG and KR with some exceptions. The estimates of heritability for ADG1, ADG2, KR1 and KR2 were low to medium (0.07±0.04, 0.14±0.06, 0.04±0.04 and 0.16±0.06, respectively) suggesting low genetic variability in the studied population. Adoption of suitable measures to reduce environmental variability can be helpful in achieving desirable growth during pre-and post-weaning period in Deccani sheep.

Estimation of genetic parameters for production traits in Munjal sheep

Astudy was carried out to estimate the genetic parameters of production traits in Munjal sheep using 16 years (2001–2016) data of 462 sheep maintained at Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar Mixed model analysis included the sire as a random effect and effects of period of birth, sex, dam's age at lambing as fixed effects. Heritability estimates and genetic correlations for different traits were calculated by paternal half-sib correlation method using sire components of variance and covariance. Period of birth and sex of lamb had significant effect (P<0.05) on all traits except greasy fleece weight (GFW). Dam's age at lambing had significant (P<0.05) effect only on birth weight. The overall least squares means of production traits recorded for birth weight (BW), weaning weight (WW), six months body weight (SMW), yearling body weight (YBW) and annual GFW were 4.1±0.07, 15.57±0.22, 20.79±0.53, 26.40±0.41 and 1.84±0.04 kg, respectively and the corresponding heritability estimates were 0.35±0.18, 0.48±0.20, 0.57±0.24, 0.48±0.25 and 0.52±0.22, respectively. Genetic correlations among production traits were positive and low to high in magnitude (0.10±0.05 to 0.76±0.05) and the highest genetic correlation of 0.76±0.05 was found between SMW and YBW. Phenotypic correlations among various production traits were found to be positive and significant ranging from 0.17±0.04 to 0.81±0.03. It was concluded that selection on the basis of SMW would be the best approach to improve growth performance in Munjal sheep as the trait has high heritability and positive genetic correlation with other body weights.

The effect of service ram on reproductive performances and birth weight of lambs

The investigation was conducted in population of Mis breed of sheep, divided into three groups. For reproduction had use rams of Ile de France breed. Induction and synchronization of oestrus was done off-season in October. The percentage of lambing sheep, sheep fertility, and number of lambs acquired per father, sex and birth type of lambs were observed. Ram 1 had a highest number of ewes lambed with an excellent percentage of mating success and highest fertility rate of ewes with differences on fertility rate of 17% (between group of ewes in ram 1 and ram 2), 36% (group of ewes in ram 1 and ram 3) and 19% (group of ewes in ram 2 and ram 3).The highest birth weight were on lambs born single from ram 3, born twins from ram1, triplets of ram 3. For the lambs born quadruplets (unfortunately only in rams 1 and 2 with one lamb of each was alive) the lamb of ram 2 was higher in birth weight. The male and female lambs of ram 3 got the highest birth weight while the female lambs of ram 1 acquired the lowest birth weight. The highest average birth weight of lambs was born single, male; born triplets? male from lambs of ram 3 having an average birth weight of 6.36kg and 4.0 kg but got the lowest for lambs born twins on female lambs 3.66 kg. The male lambs of ram 1 got the highest average birth weight on lambs born twins with an average birth weight of 4.38 kg but the lowest on triplets born 3.3kg. Unfortunately only one each of the two ram with lambs born quadruplets alive both male and the higher was that lamb of ram 2 with a birth weight of 3.3 kg. Result showed the influence of ram on number of lambs born and lambs? birth weight. Between subject effects Father* birth type showed a significant effect on birth weight of lambs.