Temporal changes in circulating levels of plasma interleukin-8 during peripartum period in Murrah buffaloes (Bubalus bubalis) under subtropical climate

The objective of this study was to elucidate the changes in circulating levels of plasma interleukin-8 (IL-8) during peripartum period in Murrah buffaloes (Bubalus bubalis). IL-8 was estimated in blood plasma of healthy peripartum Murrah buffaloes (n = 6) on days ±30, ±15, ±5, ±3, ±1 and 0 pre- and postpartum with respect to the day of parturition (day 0) in each of the two different seasons (hot–humid and spring). The mean microclimate Temperature–Humidity Index (THI) during spring season was significantly lower (p < 0.01) than the corresponding THI in hot–humid season. In both the seasons, plasma IL-8 remained lower in prepartum period (≤46.56 ± 14.08 pg/ml during spring and ≤ 73.18 ± 18.56 pg/ml during hot–humid season) than in the postpartum period (≥51.41 ± 13.82 pg/ml during spring and ≥ 84.13 ± 16.97 pg/ml in hot humid season). During spring, the IL-8 levels were significantly higher (P < 0.05) on days +5 and +15 postpartum in comparison to the IL-8 levels on days −30, −5, and −3 prepartum. During hot–humid season, IL-8 level was significantly higher (P < 0.05) on day +30 as compared to the IL-8 levels on days −30 and −5 prepartum. The correlation between IL-8 and mean microclimate THI was significant (r = 0.25, P < 0.01). From the results, it is concluded that peripartum period in buffaloes is associated with an inflammatory response leading to significantly higher plasma IL-8 during parturition and postpartum period than in the pre-partum period.     

Effects of first postpartum progesterone rise,metabolites, milk yield,and body condition score on the subsequent ovarian activity and fertility in lactating Holstein dairy cows

Seventy multiparous healthy lactating Holstein cows (fat-corrected milk yield = 7,561.8 kg) were monitored from 14 days before to 70 days after calving. Transrectal ultrasound scanning was performed twice weekly from 7 to 65 days postpartum. Blood samples were also collected twice weekly to measure serum P₄ and biweekly to detect serum β-hydroxybutyrate (βHB) and nonesterified fatty acid (NEFA) concentrations. Body condition score (BCS) was taken biweekly after calving. Based on the serum P₄ profile of 59 cows (11 cows were excluded due to the occurrence of postpartum diseases) studied, 27 (45.8%) had normal ovarian activity, while 21 (35.6%), six (10.1%), three (5.1%), and two (3.4%) had delayed ovulation (DOV), prolonged luteal phase (PLP), short luteal phase (SLP), and cessation of ovarian activity, respectively. Cows with PLP had an earlier ovulation compared to that of cows with normal ovarian activity (23.16 ± 4.02 vs 31.9 ± 8.35 days; P < 0.05). PLP cows also had a greater mean ± standard deviation peak milk yield (44.2 ± 5.8 vs 37.2 ± 5.7 kg/day, 75 days postpartum; P < 0.05) than cows with normal postpartum ovarian activity. The PLP group also had greater milk production in the previous lactation period. Logistic regression analysis indicated that cows with P₄ concentration ≥1 ng/ml on day 24 after calving were more at risk for PLP by 1.1 for each 1 kg increase in mean peak milk yield during 75 days after calving. BCS was lower in cows with DOV compared to that of cows with normal ovarian activity at any time after calving (P < 0.05). Serum βHB concentrations in DOV cows were significantly higher than that of normal cows on day 42 after calving (0.69 ± 0.29 vs 0.54 ± 0.12 mmol/L, P < 0.05). No significant difference was found in the mean concentrations of NEFA between cows in different groups at any time after calving (P > 0.05). The concentrations of P₄ on days 28 and 31 were negatively correlated with βHB concentration on day 42 after calving in cows with normal ovarian activity (R = −0.44, P = 0.02). In conclusion, these findings suggest that early ovulation and hence early postpartum P₄ rise in addition to the high milk production could partly be responsible for the occurrence of PLP in dairy cows.     

Environmental factors and interval from the introduction of rams to estrus in postpartum Saint Croix sheep

The objective of this study was to determine whether season and total rainfall during the breeding season, sheep parity, and/or litter size affect the interval from the introduction of rams to estrus (IRE) in hair Saint Croix sheep in northeastern Mexico. An analysis was made of 874 services performed during 9 years, introducing the rams into the sheep flock after an isolation period of 60 days during the postpartum period. Estrus was recorded twice daily during 35 days. Year and season influenced significantly on the interval between ram introduction and estrus length (P < 0.01). Winter IRE length (7.9 ± 0.1 days) was shorter than in the other three seasons (11.1 ± 0.2, 11.1 ± 0.1, and 16.2 ± 0.2 days in summer, autumn, and spring, respectively) (P < 0.01). An interaction was observed between rainfall and season, then by rainfall between 0 and 100 mm, IRE was shorter (P < 0.05) in winter (6.8 ± 0.3 days), and by rainfall between 100 and 199 mm, IRE was shorter (P < 0.05) in autumn (10.2 ± 0.5 days); however, when rainfall was beyond 200 mm, IRE length was shorter (P < 0.01) in summer (4.8 ± 0.5 days) than in autumn (14.5 ± 0.3 days). The IRE length was also longer in first lambing ewes (P < 0.05) and was not affected by litter size. In the present study, several factors, including the breeding season, rainfall and parity, directly influenced the interval between the male introduction and the onset of estrus by Saint Croix hair sheep.     

Thermoregulation and performance of British Anglo-Nubian and Saanen goats reared in an intensive system in Trinidad

Anglo-Nubian and Saanen goats were imported into Trinidad and Tobago to form the nucleus of the goat expansion and improvement programme. Thermoregulation and performance of the parent stock and the F1 were evaluated under intensive housing and management. Rectal temperature in the a.m. irrespective of breed or season ranged from 38.5°C to 38.7°C and p.m. ranged from 38.8°C to 39.0°C. After 2 h of exposure outdoors without shade, Saanen parent stock (SAPS) respiration rate (105 br/min) was significantly higher (p < 0.001) than Saanen F1 (SAF1, 76 br/min), Anglo-Nubian parent stock (ANSP, 65 br/min) and Anglo-Nubian F1 (ANF1, 51 br/min). Rectal temperature over the same period showed significant differences (p < 0.042) between SAF1 (39.8°C) and SAPS (39.4°C), and ANF1 (39.4°C); the value for ANSP was 39.7°C. Age at first kidding showed no significant difference (p > 0.05) between breeds or between the parent stock and the F1 generations, ranging from 638 to 686 days. The ANPS were the most prolific of all groups (p < 0.05); the mean for this group was 1.86 ± 0.07 kids/kidding. Saanen F1 was the least prolific among the group, with mean number of kids at 1.23 (±0.11) kids/kidding. Kidding interval showed no significant (p > 0.05) difference between the groups, ranging from 319 to 521 days. It was concluded that the Anglo-Nubian appears to be more suitable than the Saanen for the tropical humid environment in Trinidad as indicated by their thermoregulation, prolificacy and kidding interval.     

Plasma cholesterol levels and short-term adaptations of metabolism and milk production during feed restriction in early lactating dairy cows on pasture

Low plasma total cholesterol (TC) concentrations are characteristic during the negative energy balance in early lactating dairy cows. The objective was to investigate short-term effects of different TC concentrations during an aggravated energy deficiency through a 1-week concentrate withdrawal on adaptations of metabolism and milk production. Multiparous Holstein cows (n = 15) were investigated during 3 week beginning at 24 ± 7 DIM (mean ± SD). Cows were kept on pasture and received additional concentrate in experimental week 1 and 3, while in week 2, concentrate was withdrawn. Blood was sampled once and milk twice daily. Based on their average TC concentration during week 1 (prior to concentrate withdrawal), cows were retrospectively assigned into a high (H-Chol; n = 8, TC ≥ 3.36 mmol/L) and a low TC groups (L-Chol; n = 7, TC < 3.36 mmol/L). Concentrations of phospholipids and lipoproteins were higher in H-Chol compared to L-Chol throughout the study (p < 0.05). During concentrate withdrawal, milk yield, glucose and insulin concentrations decreased similarly in both groups, while milk fat, milk acetone and plasma BHB were higher in H-Chol compared to L-Chol (p < 0.05). Compared to initial values, plasma NEFA, TAG and VLDL increased in both groups within 2 days after concentrate withdrawal (p < 0.05). Concentrations of NEFA during week 2 were greater in L-Chol compared to H-Chol (p < 0.05). Despite reintroduction of concentrate, milk yield in H-Chol remained lower for two more days compared to week 1 (p < .05), whereas milk yield recovered immediately in L-Chol. Activity of aspartate aminotransferase was higher in H-Chol compared to L-Chol in week 2 (p < 0.05). Greater plasma TC concentrations were associated with a reduced increase of NEFA. Further research is warranted if TC concentrations are related to adipose tissue mobilization and fatty acid turnover.     

Absence of Any Specific Diurnal Pattern in the Time of Ovulation in the Mare

This study investigates a long-held belief that mares tend to ovulate during the night. If this were so, a strategic examination regimen might replace multiple daily examinations when the time of ovulation needs to be known to within a few hours. Over 500 mares were examined at least three times daily to determine the time, to within ±4.25 hours, of 896 ovulations. The time of ovulation was determined as midway between the pre-ovulatory and post-ovulatory examinations. Three broad peaks of incidence of ovulation occurred at 5:00 am, 2:00 pm, and 10:00 pm. The interval between peaks was 9, 8, and 7 hours. during which 34.2% (5:00 am to 2:00 pm), 44.3% (2:00 pm to 10:00 pm), and 21.3% (10:00 pm to 5:00 am) of ovulations occurred. The percentage of ovulations occurring in the period 2:00 pm to 10:00 pm was significantly higher (P < .001) than in the period 10:00 pm to 5:00 am and significantly higher (P < .01) than in the period 5:00 am to 2:00 pm. The data showed that mares ovulated at all times of the day and night, with some increased incidence between 2:00 pm and 10:00 pm. Therefore, no strategic examination regimen was possible.     

Effect of doe milking and supplementation using <Emphasis Type="Italic">Dichrostachys cinerea</Emphasis> pods on kid and doe performance in grazing goats during the dry season

Effects of supplementation and milking of Matebele does four weeks pre-partum to weaning, on milk yield, kid birth weight and growth rate were studied. Forty does were divided into four treatments: supplemented and milked (SM), supplemented and not milked (SNM), not supplemented and milked (NSM); and not supplemented and not milked (NSNM). Supplemented goats were given 200 g/doe/day of Dichrostachys cinerea pods containing 19% CP. The study was carried out in September during time of feed unavailability and animals were grazed on rangelands for seven hours before being given the supplement. Fifty-six kids were born from all the experimental animals and 24 were singles whereas 32 were twins. Milk yield was higher (P < 0.05) in supplemented than non-supplemented does. Although supplementation had no effect on kid birth weights, growth rates were higher (P < 0.05) in the SNM group (103 ± 10.1 g/day) than in the SM group (74 ± 10.8 g/day). Among the non-supplemented groups, kids from milked does had higher (P < 0.05) daily gains (85 ± 10.9 g/day) than those from non-milked does (67 ± 10.7 g/day). Weaning weights were higher (P < 0.05) in SNM does (12.8 ± 1.30 g/day) than in the SM does (10.2 ± 1.17 g/day). Among kids from the non-supplemented does, those from milked does had superior (P < 0.05) weaning weights (11.2 ± 1.23 g/day) than those from non - milked does (9.2 ± 1.27 g/day). Mortalities were also lowest in kids born from SNM does. It is concluded that pre-partum to weaning supplementation generally increases milk production which then increases kids growth rates and weaning weights, as well as reduce kid mortalities.     

Behaviour of crossbred does and their kids at parturition under extensive and intensive conditions

Data from 82 kiddings from mixed-breed (native x dairy goats) goats reared on rangeland (n = 47) or confinement (n = 35) were used to determine the influence of various factors on length of labour, standing of newborn kids and time to first suckling in pluriparous goats. Both groups were mated at the same time to bucks of the same genotype in February. During the kidding time in July, the goats were monitored for 24 h in order to register parturition traits and kid birth weight and body measurements. For all goats, blood samples were collected at parturition in order to establish the nutritional state of goats. Grazing goats had lower body weight and body condition score (P < 0.01) than pen-fed goats, as well as lower values for some blood metabolites indicative of low body energy reserves. For both grazing and pen-fed goats, the majority of kiddings (>93%) occurred during daylight hours. No kiddings were registered from 2300 to 0500 hours. No effects of height at withers, thoracic circumference and sex of kids at birth were found to influence length of labour. Labour was shorter (P < 0.01) for pen-fed does than grazing goats (10.6 ± 1.18 min vs. 15.4 ± 1.2 min; mean ± SD). The length of parturition was considerably longer (P < 0.05) for twin-bearing does than for single-bearing does (16.6 ± 1.76 min vs. 11.2 ± 0.81 min, respectively). The interval between parturition and standing of kids was shorter (P < 0.05) for kids from litters weighing >3.3 kg (entire litter) than kids from litters with <3.3 kg (22.7 ± 1.82 min vs. 31.1 ± 2.76 min). Time to first suckling was longer (P < 0.05) for kids delivered from pen-fed does than kids from grazing does (57.8 ± 7.57 min vs. 42.9 ± 3.05 min). These results confirm that, independently of type of production system (intensive or extensive), kiddings of does are concentrated during daylight hours. These results also indicate that conformation of kids does not alter duration of labour, and that nutritional stress of goats during gestation (extensive conditions) does not interfere with the neonate’s level of alertness and arousal.     

Analysis of size and conformation of native Creole goat breeds and crossbreds used in smallholder agrosilvopastoral systems in Puebla,Mexico

Liveweight (LW) of does and bucks of the native Creole goat breed and crosses of Creole does and Nubian bucks, aged 1.5–5 years, were recorded and body traits including: head length (HL), head width (HW), body length (BL), trunk length (TL), chest girth (CG), abdominal perimeter (AP), rump length (RL), and height at withers (HW) were measured to develop equations for predicting LW from the body measurements. Weight, sex, breed and kidding date of 354 kids were recorded at birth, and LW of the kids was measured monthly for one year to determine the effect of kidding season on growth rate. Bucks had higher (p < 0.05) body measurements than the does (HL 15.1 ± 0.1 vs 16.6 ± 0.2 cm; BL 97.6 ± 0.4 vs 104.6 ± 1.2 cm; CG 78.8 ± 0.4 vs 79.9 ± 1.0 cm; AP 82.4 ± 0.5 vs 87.2 ± 1.1 cm; HW 62.7 ± 0.4 vs 70.1 ± 0.8 cm). With the exception of TL, F₂ does had higher (p < 0.05) body measurements and LW (28.8 ± 1.5 vs 27.7 ± 0.5 kg) than Creole does. The body traits of the F₁ does were similar (p > 0.05) to those of Creole does with the exception of HL, BL and HR. The F₂ kids were heavier (p < 0.05) at birth (3.31 ± 0.1 vs 2.60 ± 0.1 kg) and grew faster than the Creole kids. Male kids were heavier (p < 0.05) at birth (3.21 ± 0.10 vs 2.73 ± 0.13 kg), and grew faster than female kids. Season had a significant effect on birth weight. The results showed that LW of Creole goats and Creole × Nubian does could be estimated in the field using body traits. Birth weight and growth rate of kids could be improved by management practices that affect season of kidding.     

Recovery from adverse effects of heat stress on slow-growing chicks in the tropics 1: Effect of ascorbic acid and different levels of betaine

Three hundreds, 21 d-old slow-growing chicks were randomly divided among 5 treatments, of 5 replicates each. Each replicate contained 12 unsexed chicks housed in (1 × 1) a floor pen. A group was kept under thermoneutral condition at 28 ± 4°C and RH was 55 ± 3% during 21–84 d of age (positive control) and fed corn-soybean meal diet. The other four groups were kept for three successive days per week under heat stress (HS) at 38 ± 1.4°C and 49 ± 2% RH from 12.00 to 16.00 pm. Chicks in HS treatments were fed corn-soybean meal diet without (negative control) or with 250 mg AA/kg diet and Bet at 0.5 and 1 g/kg diet. HS decreased productive performance, increased (P < 0.05) meat dry matter, plasma triglyceride and serum calcium whereas decreased (P > 0.05) plasma glucose, serum total protein and water holding capacity (WHC) of meat. AA and 1 g of Bet/kg diet was equally potent for partial relief (P < 0.05) of the negative effect of HS on growth, increased (P < 0.05) feed intake, protein digestibility (P < 0.05), dressing out percentage, liver and giblets, whilst improved (P < 0.05) feed conversion ratio (FCR). Also, a complete recovery from the negative effect (P < 0.05) of HS shown on plasma glucose and partial recovery (P < 0.05) observed in total protein, triglyceride, blood pH, packed cell volume (PCV), hemoglobin (Hgb), rectal temperature (RT) and respiration rate (RR) and improved humoral immune competence to sheep red blood cell (SBRCs) test.     

Effect of supplementation with urea,blood meal,and rumen-protected methionine on growth performance of Holstein heifers grazing kikuyu pasture

Supplements with corn grain, molasses cane, and different nitrogen sources were evaluated in 16 growing Hosltein heifers [227 ± 33 kg body weight (BW)] grazing kikuyu (Pennisetum clandestinum) pasture in a 10-ha sward (rotational grazing with electric fences) during 90 days in the summer season. The nitrogen sources were urea (U); urea and blood meal (U + BM); and urea, blood meal, and rumen-protected methionine (U + BM + RPM). Heifers were randomly assigned to four experimental supplements defined as follows: control (no supplementation), U, U + BM, and U + BM + RPM. Two kilograms (as fed) of supplement was offered daily. The final BW of heifers fed U + BM + RPM was higher (P < 0.05) than heifers not supplemented. The total and average daily weight gain of heifers supplemented with U + BM + RPM were higher than heifers not supplemented or supplemented with U and U + BM (P < 0.05). The average daily gain of heifers supplemented with U and U + BM were higher than heifers not supplemented (P < 0.05). Grass intake was not affected by supplementation, but total dry matter intake was increased by supplements with U, U + BM, and U + BM + RPM (P < 0.05). Feed conversion was improved by U + BM + RPM (P < 0.05). Total tract digestion was not affected by supplements. Blood urea nitrogen concentrations of heifers supplemented with U, U + BM, and U + BM + RPM were higher than heifers not supplemented (P < 0.05). It is concluded that supplements with U + BM + RPM improved growth performance and feed conversion in heifers grazing kikuyu pasture.     

Growth performance and carcass characteristics of indigenous Mukota pigs of Zimbabwe

Carcass quality characteristics are essential in affecting grading and revenue that pig producers realize. No information is available on the grading of carcasses in indigenous Mukota pigs of Zimbabwe. The objective of this study was to determine the influence of genotype (Mukota and Large White × Mukota) and sex on post-weaning growth performance and carcass traits of pigs fed maize cob-based diets. All pigs were weighed at 2-week intervals to estimate average daily gain, dressing percentage (DP), and carcass lengths. Backfat thickness was also measured. Males had higher body weight gains than females (P < 0.05). Growth rates for Mukota (0.31 ± 0.010) and crossbred (0.41 ± 0.030) pigs were lower in the cool season than the other seasons (P < 0.05). Body weights were consistently higher in the crossbred than in the Mukota pigs (P < 0.05). Mukota pigs showed a peak growth between 12 and 14 weeks post-weaning (P < 0.05). The DPs were 0.70 and 0.73 for the Mukota and crossbred pigs, respectively (P < 0.05). Crossbred pigs had longer (P < 0.05) carcasses than Mukota (655.5 ± 1.68 versus 507.2 ± 0.92 mm). Although there were no differences in the backfat thickness between males and females of the crossbred pigs, Mukota males had thicker backfat than the females (P < 0.05). Crossbreeding is, therefore, significant in improving carcass grades of Mukota pigs.     

Relationship of age to body weight,scrotal circumference,testicular ultrasonograms,and semen quality in Sahiwal bulls

The objective of the present study was to determine the relationship of age to body weight (BW), scrotal circumference (SC), number of pixels of testicular ultrasonograms (NP), and semen quality in Sahiwal bulls. The study was based on 128 Sahiwal bulls of different age groups (from 0 to >100 months of age). Bulls were evaluated for SC, BW, and NP. Semen was evaluated once a week for five consecutive weeks from regularly collected donor bulls (n = 86) ranging in age from 25–30 to >100 months. Ejaculate volume, sperm motility, sperm concentration, sperm morphology, percent live sperms, sperm plasma membrane integrity, and normal acrosome were compared among different age groups. Mean SC and BW increased (P < 0.05) in a curvilinear manner from birth to >100 months of age. Mean NP of testicular ultrasonograms increased (P < 0.05) from 0 to 24 months and then plateaued until >100 months of age. Body weight, SC, and NP were positively correlated with age from birth until >100 months (r = 0.91, 0.87, and 0.40, respectively). Ejaculate volume (5.7 ± 0.2 vs. 4.6 ± 0.09 ml) and sperm concentration (1,281.6 ± 17.7 vs. 1,115.8 ± 55.9 × 10⁶/ml) increased (P < 0.05) in mature bulls compared to younger ones. However, motility (68.6 ± 0.3%), plasma membrane integrity (50.8 ± 1.0%), and normal acrosome (74.8 ± 0.5%) remained insignificant due to age. In six of eight age groups studied, morphological abnormalities were well within the range (18.1 ± 0.3%). In conclusion, the BW, SC, and NP of testicular ultrasonograms, ejaculate volume, and concentration increased with age. Moreover, semen quality is fairly independent of age except volume and concentration in Sahiwal bulls.     

Milk production and blood metabolites of dairy cattle as influenced by thermal-humidity index

The effects of high thermal stress on serum protein metabolites, milk production of transition dairy cows in semi-arid areas in South Africa were evaluated. Forty, ±?8 months pregnant, Jersey heifers (±?26 months) in zero grazing management were selected during summer from two semi-arid communal areas. Summer thermal-humidity index (THI) of the areas were THI-1 (72–83: extreme caution) and THI-2 (75–87: danger). Blood samples were collected (21 days pre-partum, and 21 and 75 days post-partum) and analysed for serum protein metabolites. Milk yield was recorded daily and samples collected for milk fat, protein, lactose and urea nitrogen analysis. Heifers in THI-2 had lower (P?<?0.05) total serum proteins, albumin and blood urea nitrogen than THI-1. Post-calving, cows in THI-1 had higher (P?<?0.05) TP (73.4 vs 67.9 g/l) and BUN (4.61 vs 3.77 mmol/l) at 21 DIM, and lower (P creatinine at 21 and 75 DIM than THI-2 group. Milk yield, fat and protein in THI-2 were all lower (P?<?0.05) than THI-1 21DIM. The results confirm that heat stress affects utilisation of nutrients in transition dairy cows.

     

Effect of ruminally protected methionine on body weight gain and growth of antlers in red deer (<Emphasis Type="Italic">Cervus elaphus</Emphasis>) in the humid tropics

Sixteen male red deer (Cervus elaphus), with an initial weight of 93.83 ± 4.38 kg were used to study the effect of the dietary level of ruminally protected methionine (RPM) on growth, antler morphometry and serum metabolites. The deer were allowed to graze and were individually supplemented with concentrate to provide 0, 2.5, 3.5 or 4.5 g/day of RPM for 65 days. There was a quadratic effect on daily weight gain (0.163, 0.098, 0.147 and 0.172 kg/day; P < 0.005) and antler beam length (59.7, 63.6, 63.0 and 57.2 cm; P < 0.02) for RPM levels of 0 to 4.5 g/day, respectively. The brow tine length and the number of points were similar across all treatments. Serum glutamic pyruvate transaminase (SGPT) was reduced (quadratic effect; P < 0.02; 22.0, 29.6, 18.0 and 17.8 IU/l) to RPM levels of 0 to 4.5 g/day, respectively, whereas other metabolites (glucose, cholesterol, urea, creatinine, total protein and serum glutamic oxaloacetic transaminase [SGOT]) were unchanged. Increasing the RPM dose did not affect weight gain or antler growth. Methionine supplementation reduced the activity of SGPT.     

Effect of protein supplementation on reproductive and productive performance in <Emphasis Type="Italic">Bos indicus</Emphasis> × <Emphasis Type="Italic">Bos taurus</Emphasis> heifers raised in the humid tropics of Costa Rica

In order to evaluate the effect of protein supplementation on the productive and reproductive performance of heifers, 45 Bos indicus × Bos taurus heifers, 673 ± 146 days of age and weighing about 340 kg, were divided into two groups. The control group (n = 23) continued without supplementation, but the supplemented group (SG; n = 22) received concentrate at a rate of 1% BW kg per day. Animals were adapted to the concentrate over a 15-day period and then supplemented for 30 days, after which estrus was synchronized using a progesterone implant. Back fat thickness (BFT) was assessed by ultrasound. The SG had better average daily weight gain than the nonsupplemented group (0.63 ± 0.16 vs. 0.51 ± 0.13 kg/day, P < 0.05) and tended to show a better percentage ovulation (P < 0.10, 77% vs. 57%, respectively). However, this tendency was not reflected in the final pregnancy rates. No differences were observed between groups in dry matter intake and body condition scores. SG with a high BFT (>0.70 cm) showed a better ovulation percentage than those with low BFT (<0.69 cm; P < 0.01). Additionally, the pregnancy rate of supplemented heifers with high BFT tended to be better than heifers with low BFT in this same group (67% vs. 30%, respectively, P < 0.10). It is concluded that protein supplementation improved reproductive performance and that ultrasonography to measure BFT may be used to estimate reproductive performance.     

Efficiency of two timed artificial insemination protocols in Murrah buffaloes managed under a semi-intensive system in the tropics

The objective of the study was to determine the efficiency of ovsynch (OV) versus presynch-ovsynch (P-OV) protocol for synchronization of ovulation and timed artificial insemination (TAI) in female buffaloes. The OV group (n = 40) received gonadotrophin-releasing hormone (GnRH) on day 0 (random day of the estrous cycle), prostaglandin ( PGF_2a ) \left( {{\hbox{PG}}{{\hbox{F}}_{2\alpha }}} \right) on day 7 and a second GnRH administration on day 9 followed by a single artificial insemination (AI) 16-20 h later. The P-OV group (n = 40) received two PGF_2a {\hbox{PG}}{{\hbox{F}}_{2\alpha }} injections 14 days apart, with the second injection administered 14 days before starting the OV protocol. Progesterone (P₄) was measured at the time of PGF_2a {\hbox{PG}}{{\hbox{F}}_{2\alpha }} administration (within the OV protocol) and AI. Neither ovulation rate ((24 h after TAI) OV 90%-36/40 vs. P-OV 85%-34/40) nor pregnancy rates ((day 60 after TAI) OV 35%-14/40 vs. P-OV 45%-18/40) differed between the two protocols. Pregnant buffaloes had lower concentrations of P₄ at AI compared with non-pregnant animals in the OV group (0.7 ± 0.1 vs. 1.1 ± 0.1 ng/ml); but in the P-OV group, differences did not reach statistical significance (0.8 ± 0.1 vs. 1.0 ± 0.1 ng/ml). This apparent trend reached statistical significance when the analysis was carried out in animals from both protocols (0.7 ± 0.1 (pregnant) vs. 1.1 ± 0.1 (non-pregnant) ng/ml). In conclusion, both protocols synchronize ovulation effectively with no significant differences in conception rates. High concentrations of P₄ at AI seem to be detrimental for the establishment of pregnancy in lactating buffalo cows.     

Prevalence and biology of goat warble fly infestation by <Emphasis Type="Italic">Przhevalskiana silenus</Emphasis> in Jammu province,India

Examination of 3,960 goats brought from six districts of Jammu province and slaughtered at Jammu abattoir from July 2005 to June 2006 revealed 47.22% prevalence of larval stages of warble fly (Przhevalskiana silenus Brauer, 1858) in goats. Highest prevalence was recorded in Udhampur (56.44%) and lowest in Doda district (13.49%). Classification of the study area into four zones based on height (meters above sea level), viz., zone I (300–325 m asl), zone II (325–800 m asl), zone III (800–1,500 m asl), and zone IV (>1,500 m asl), revealed significant (p < 0.01) difference in infestation among animals of zone II (71.68%), zone III (40.12%), and zone IV (22.41%). However, animals of zone I did not reveal any infestation. Statistical analysis in relation to age showed significant (p < 0.01) difference among different age groups, i.e., <1 year (2.81%), 1–3 years (51.17%), and >3 years (43.16%). Breed-wise analysis also showed significantly (p < 0.01) higher infestation rate among Bakerwali (51.51%) goats as compared to Beetal (42.59%). But no significant difference was recorded among male (47.81%) and female (46.82%) animals. The overall mean larva count (L1, L2, and L3) was observed to be 14.72 ± 0.34, ranging from 4 to 72. It was significantly (p < 0.05) higher in animals of zone II (22.20 ± 0.21) as compared to goats of zones III (14.21 ± 0.41) and IV (7.73 ± 0.90). Age-wise analysis of mean larva count also showed significant (P < 0.05) difference between animals of 1–3 years (16.25 ± 0.37) and >3 years of age (13.18 ± 0.40). Mean larvae count in relation to sex and breed did not reveal any significant difference. First-instar larvae (L₁) were recorded from May to mid-September, second larval stage (L₂) from mid-September to mid-December, and third-stage larvae (L₃) from mid-December to February. However, No larvae were recorded from March to April, which is suggestive of pupation period in this region. Thus, it is concluded that adult fly is active in April to June. The results further confirmed that internal life cycle of P. silenus is subcutaneous and no migration of larvae occurs. This is the first report from India, based on slaughter house study on the prevalence and biology of goat warble fly infestation. It will help in devising suitable prophylactic and eradication program to check the economic losses rendered by adult fly.     

Estimates of phenotypic and genetic parameters for birth weight of Brown Swiss calves in Turkey using an animal model

A study was conducted to assess the influence of genetic and environmental factors on Brown Swiss calf birth weight, and to estimate variance components, genetic parameters, and breeding values. Data were collected on 1,761 Brown Swiss calves born from 1990 to 2005 in the Konuklar State Farm in Turkey. Mean birth weight for all calves was 39.3 ± 0.09 kg. Least squares mean birth weights for male and female Brown Swiss calves were 40.3 ± 0.02 and 39.0 ± 0.02 kg, respectively. Variance components, genetic parameters, and breeding values for birth weight in Brown Swiss calves were estimated by restricted error maximum likelihood (REML)–best linear unbiased prediction(BLUP) procedures using an MTDFREML (multiple trait derivative free restricted maximum likelihood) program employing an animal model. Direct heritability (h _d²), maternal heritability (h _m²), total heritability (h _T²), r _am and c _am estimates were 0.12, 0.09, 0.23, −0.58, and −0.06, respectively. The estimated maternal permanent environmental variance expressed as a proportion of the phenotypic variance (c ²) was 0.05. Breeding values were estimated for the trait and used to evaluate genetic trends across the time period investigated. The genetic trend linear regression was not different from zero. No genetic trend for birth weight was expected, since there had been no direct selection pressure on the trait. Absence of a trend confirms that there was no change due to selection pressure on correlated traits. Genetic and environmental parameter estimates were similar to literature values indicating that effective selection methods used in more developed improvement programs would be effective in Turkey as well.     

Intake,digestibility and rumen dynamics of neutral detergent fibre in cattle fed low-quality tropical forage and supplemented with nitrogen and/or starch

The objective of this work was to evaluate the effects of nitrogenous compounds and/or starch supplementation on the intake, digestibility and rumen dynamics of neutral detergent fibre (NDF) in cattle fed low-quality tropical forage. Four crossbred heifers (Holstein × Zebu) with a body weight 231.9 ± 15.5 kg and fitted with ruminal cannulae were used. The forage fed to the animals consisted of low-quality signal grass (Brachiaria decumbens Stapf.) hay, with an average crude protein (CP) level of 51.6 g/kg, on a dry matter (DM) basis. Four treatments were evaluated: control, without supplementation; supplementation with nitrogenous compounds (CP of the roughage was raised to 100 g/kg), on a DM basis; supplementation with starch at a ratio of 200 g/kg DM of roughage; and supplementation with nitrogenous compounds and starch as described above. A mixture of urea, ammonium sulphate and albumin was used as a source of nitrogenous compounds at a ratio of 4.5:0.5:1.0. The experiment was carried out according to a 4 × 4 Latin square design in a 2 × 2 factorial arrangement. There was a positive effect of the nitrogenous compound supplementation on the DM and NDF intake (P < 0.01). In contrast, starch supplementation decreased forage intake (P < 0.10). Nitrogen supplementation increased the digestibility coefficient of DM and NDF (P < 0.05). Supplementation with nitrogen and starch together increased the microbial assimilation of nitrogenous compounds in the rumen (P < 0.05). We observed that nitrogen supplementation increased the estimated weighted degradation rate of NDF by 14.8%, whilst starch supplementation decreased this rate by 32.5%.