The impact of genetic merit on ewe performance and efficiency parameters

The aim of this study was to investigate the impact of ewe genetic merit on ewe performance and efficiency parameters. The study consisted of three genetic merit groups (New Zealand [NZ], High Irish, and Low Irish) and ran from 2016 to 2019, inclusive. Each genetic merit group contained 30 purebred Suffolk and 30 purebred Texel ewes, which were selected based on their maternal genetic indexes in their country of origin, namely Ireland (€uro-star Replacement index) or New Zealand (New Zealand Maternal worth). Ewe body condition score (BCS), ewe body weight (BW), milk yield, milk composition, dry matter intake (DMI), and efficiency parameters were all analyzed using linear mixed models. Ewe BW was similar across all genetic merit groups at each time point (P > 0.05). In comparison to both High and Low Irish ewes, NZ ewes had a higher BCS at mating, mid-pregnancy, lambing, week 10 post-lambing (PL, P < 0.05). Ewe BW change was similar across genetic merit groups, except between mating and mid-pregnancy where ewe BW loss was greater for NZ ewes than Irish ewes (P < 0.05) and between weeks 6 PL and 10 PL, where NZ ewes gained BW and High and Low Irish ewes lost BW (P < 0.01). Ewe milk yield, milk fat, total solids, and gross energy content were superior for milk produced by NZ ewes at week 6 PL in comparison to milk produced by High Irish and Low Irish ewes (P < 0.01). NZ ewes produced a greater quantity of milk solids/kg of BW at week 6 PL compared with High Irish ewes (P < 0.01), whereas Low Irish ewes did not differ from either NZ or High Irish (P > 0.05). Low Irish ewes had a greater daily DMI than High Irish ewes in late lactation (week 10 PL, P < 0.05) and had a greater DMI/kg of ewe BW compared with the High Irish ewes at the same time point (P < 0.05). NZ ewes weaned a litter BW equivalent to 60.4% of their mating BW, which was more than the Low Irish ewes who weaned 57.1% of the ewe’s BW at mating (P < 0.01), whereas the High Irish ewes did not differ from either the NZ or Low Irish ewes at 59.3% of the ewe’s BW at mating (P > 0.05). This study presents a range of parameters across ewes of high and low genetic merit, demonstrating the ability to achieve gains through selection of animals of high genetic merit. Sheep producers should consider genetic indexes as a tool to assist in the decision-making process of selecting replacement ewes and/or breeding rams, once satisfied the animal is correct, and meeting the breeding objectives of the system.     

The effect of high calcium intake by pregnant Awassi ewes at late gestation on minerals status and performance of ewes and newborn lambs

Calcium (Ca) requirement increase rapidly by pregnant ewes at late gestation as a result of high fetal growth. Furthermore, Ca deficiency results in poor growth and bone development in growing newborn lambs. The aim of this study was to evaluate the effect of calcium supplementation (Calcium carbonate–CC) and vitamin AD₃E injection (75,000 IU/shot) to pregnant Awassi ewes at late gestation (− 45 days prepartum) on their mineral levels and performance of their newborn lambs. Forty pregnant Awassi ewes at late gestation (65 ± 6.1 kg) were selected before parturition (− 45 days; using hormonal sponges for estrus synchronization) and randomly divided to 4 dietary treatments. The treatments were: group 1 Control (1.4% CC); group 2 (2.4% CC); group 3 (1.4% CC + 2 shots vitamin AD3E at − 45 and − 21 days prepartum); group 4 (2.4% CC + 2 shots vitamin AD3E at − 45 and − 21 days prepartum). Blood samples were collected from ewes (− 45, 0 days prepartum: 30 and 60 days postpartum) and lambs (0, 30 and 60 days old). Average milk yield and samples were collected. Body weights of lambs were taken at birth, 30 and 60 days old. Blood serum and milk samples were prepared and analyzed by AAS for Ca, Mg, Co, Mn and Cu concentrations.Calcium concentrations in bloods serum of ewes, 0 and 60 days postpartum, and lambs at weaning (60 days old) from group 4 were significantly (P < 0.05) higher compared to other groups. No significant effect (P > 0.05) of treatment on Co, Mg and Cu in blood serum of ewes and lambs except for Cu concentration in ewes. Moreover, a significant increase (P < 0.01) in milk inorganic% (30 and 60 days samples) in ewes from group 2 when compared with other groups. The average milk yield (AMY) of ewes from group 2 and 4 at late stage of lactation (45–60 days) were significantly higher (P < 0.05) compared to groups 1 and 3. In addition, Ca% in colostrums samples from ewes in groups 2 and 4 were significantly higher (P < 0.01). The average daily gain (ADG) and total body gain for lambs up to weaning (60 days old) were significantly higher (P < 0.05) in groups 1 and 2 compared with the other groups.In conclusion, increasing level of Ca intake in feed of Awassi ewes at late gestation, with or without vitamin AD₃E injections, improve the calcium concentration in colostrums and blood serum of ewes and their lambs without negative effect in their health and performance.     

Effects of Ca salt supplementation on milk yield and composition and on lamb growth rate of Awassi ewes

An experiment was conducted to evaluate the effect of a Ca salt supplement on lactating Awassi ewes and their lambs. Ninety Awassi ewes (average BW = 55 kg ± 1.13) were allocated into three treatment groups of 30 each; 0%, 3%, or 5% Ca salt supplemented groups. The experiment started at lambing and lasted for 60 d. During this period, milk production and composition, final body weights, total feed intake, serum cholesterol and triglycerides, weaning weights of lambs, and milk fatty acid profile were tested. Milk production and energy corrected milk increased (P < 0.05) with Ca salt level in the diet. Milk fat content was higher (P < 0.05) at 3% treatment group compared to 0% and 5% treatment groups. However, no differences were detected in content of crude protein and total solids, and milk energy value. Milk fat yield (g/d) increased (P < 0.05) as Ca salt in the diet increased. Final body weight was higher (P < 0.05) for 5% group when compared to the 0% group with no differences between the 3% group when compared to 0% and 5% groups. No differences were observed in feed intake of ewes. Metabolizable energy intake was greater (P < 0.05) for the 3% and the 5% treatment groups when compared to the 0% treatment group. Feed to milk ratio increased (P < 0.05) when increasing the level of Ca salt in the diet. Serum cholesterol was greater (P < 0.05) in the 5% treatment group than the 0% and 3% treatment groups for ewes and lambs. Serum triglyceride was similar among treatment groups in ewes whereas serum triglyceride was greater (P < 0.05) for lambs in 5% treatment group than 0% and 3% treatment groups. However, serum triglyceride was similar in ewes among treatment groups. Weaning weights and average daily gain of male lambs were higher (P < 0.05) in lambs fed Ca salt (3% and 5%) when compared to 0% treatment group. No differences were detected in weaning weights and average daily gain of female lambs among treatment groups. However, milk conversion ratio was better (P < 0.05) for the 5% group lambs than the 0% and 3% treatment groups. Ca salt reduced (P < 0.05) short and medium-chain milk fatty acids and increased (P < 0.05) content of long chain and unsaturated ones. These results of this indicate that Ca salt supplementation can improve milk production of lactating ewes, the growth rate of their lambs, and produce healthy quality value milk.     

Milk yield and composition of lactating Comisana ewes fed total mixed rations containing nitrogen sources with different ruminal degradability

The objective of this study was to examine the effects of pelleted total mixed rations (PTMR) containing two crude protein (CP) levels and N sources with different ruminal degradability on milk yield and composition of lactating ewes. The experiment, which lasted 14 weeks, was conducted during the spring and summer of 2007 and used 80 multiparous Comisana ewes in mid-lactation, reared in permanent stabling. A 2 × 2 factorial design was used, with ewes receiving two levels of CP (low 15.5% CP and high 17.5% CP) and two type of N sources with different rumen degradable protein (low and high) for each dietary treatment: (1) high-degradable protein diet (17.5% CP) composed by soybean meal, sunflower meal and urea (HPHD), (2) low-degradable protein diet (17.5% CP) included only corn gluten meal (HPLD), (3) high-degradable protein diet (15.5% CP) composed by soybean meal, sunflower meal and urea (LPHD), and (4) low-degradable protein diet (15.5% CP) included only corn gluten meal (LPLD). In order to evaluate in vivo digestibility of PTMRs, four adult rams were placed in metabolic cages and their individual faeces and urine were collected. In the performance trial, ewe milk yield was recorded daily and Individual milk samples were analysed weekly for milk composition and to determine milk renneting parameters. The 17.5% CP diets led to better nutrient apparent digestibility coefficients and had positive effects on milk production than the 15.5% CP diets. Similar results were obtained for corn gluten meal diets, compared to diets containing soybean meal, sunflower meal and urea. Data showed that corn gluten meal diets have had a positive effects on milk fat (P < 0.05), but not on milk protein, lactose and renneting parameters. All ewes gained weight during the experimental period, but the body weight change was not significant among treatments. Our findings indicate that an increase in rumen undegradable protein (RUP) content does not negatively affect nutrient digestibility of sheep rations and milk yield and composition.     

Factors affecting the milk yield and composition over lactation of prolific D’man ewes in Tunisian oases

This work aimed to investigate milk potentiality and the influence of some non-genetic factors both on milk yield production and composition in prolific D’man sheep. Observations were performed in eighty lactating D’man ewes maintained under an intensive oases system in Southern Tunisia. Daily milk yield was determined at 7-day intervals using oxytocin?+?hand milking method. Chemical milk composition was determined by Lactoscan. Total productions over lactation (milk, fat, and protein) were estimated using the Fleischmann method. Daily milk yield averaged 1.64?±?0.02 l. It increased to a plateau from the third to the fourth week of lactation, and decreased gradually to the tenth week. D’man ewes produced 128.91?±?3.14 l of milk, 9.23?±?0.26 kg of fat, and 5.26?±?0.12 kg of total proteins. Overall, milk contained 16.17% of total solids, 7.08% of fat, 4.04% of proteins, 4.32% of lactose, 9.09% of solids-not-fat, and 0.73% of ash. Lambing season affected the daily milk yield and milk composition, where fat and total proteins were highest in autumn. Total solids, lactose, solids-not-fat, and ash were higher in winter than in autumn and summer. Ewes reared multiple lambs produced more milk than those reared singles. Dams nursing triplets or more had the highest milk total proteins, and the lowest total solids and fat levels. Adult ewes produced more milk compared to younger and older ewes, and their milk contained higher total solids, fat, and ash levels than milk from young ewes. Ewes with asymmetric udder produced less and more concentrated milk than ewes with symmetrical udder. Daily milk yield was negatively correlated to total solids, fat, and total proteins amounts. In contrast, litter survival at weaning was positively correlated to the amounts of total milk, fat, and total proteins.

     

The effect of dietary supplementation with rumen‐protected methionine alone or in combination with rumen‐protected choline and betaine on sheep milk and antioxidant capacity

This study investigated the effects of dietary inclusion of rumen‐protected methionine alone or in combination with rumen‐protected choline and betaine on: (i) milk yield, chemical composition and fatty acids (FA) profile and (ii) blood plasma glutathione transferase (GST) activity of periparturient ewes. Furthermore, the oxidative stress indicators for measuring total antioxidant and free radical scavenging activity [ferric reducing ability of plasma (FRAP) and 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) assays] were also determined in plasma and milk of ewes. Thus, 45 ewes were divided into three equal groups. Each animal of the control group fed daily with a basal diet. The same diet was offered also in each animal of the other two groups. However, the concentrate fed to M group was supplemented with 2.5 g/kg rumen‐protected methionine, while the concentrate fed to MCB group with 5 g/kg of a commercial product which contained a combination of methionine, choline and betaine, all three in rumen‐protected form. The results showed that the M diet, compared with the control, increased significantly the ewe's milk fat and the total solids content. Likewise, a tendency for higher milk fat and total solids content in ewes fed the MCB diet was also observed. Both M and MCB diets had not noticeable impact on ewes milk FA profile. Significantly higher FRAP values in the blood plasma of ewes fed the MCB and in the milk of ewes fed with the M diet compared with the control were found. Additionally, significantly higher GST activity in the blood plasma of ewes fed the M diet, compared with the control, was observed. Moreover, a significant increase (by 20%) and a tendency for increase (by 16.72%) in the growth rate of lambs nursing ewes fed with M and MCB diets, respectively, compared to controls, were found.     

Dietary cation and anion difference: Effects on milk production and body fluid distribution in lactating dairy goats under tropical conditions

This study aimed to determine the effect of dietary cation and anion difference (DCAD) on milk production and body fluid distribution in lactating dairy goats. Ten dairy goats were selected and divided into two groups, five animals each. Animals received either control DCAD (control, 22.81 mEq/100 g dry matter (DM)) or high DCAD (DCAD, 39.08 mEq/100 g DM). The results indicated that rectal temperature (Tr), respiration rate, milk yield and compositions did not differ between groups. But the percentage change of Tr from the DCAD group was lower than the control group between 09.00 and 13.00 hours. DM intake tended to increase in the DCAD group. Dairy goats in the DCAD group drank more water, but urinary excretion and plasma antidiuretic hormone concentration remained unchanged. Apparent water balance was higher from the DCAD group over 24 h. There was no effect of DCAD on plasma and blood volumes, but tended to increase in extracellular fluid and thereby increased total body water. The present results indicate that animals supplemented with high DCAD increase their total body water and apparent water balance. These results have contributed to the process of adaptation for evaporative cooling and would be useful in slowing down the elevation in Tr.     

Effect of feeding dried distillers' grains with solubles on milk yield and milk composition of cows in mid‐lactation and digestibility in sheep

We evaluated the effect of three sources of dried distillers' grains with solubles (DDGS) in diets of mid‐lactating dairy cows on milk production and milk composition and on digestibility in sheep. DDGS from wheat, corn and barley (DDGS₁), wheat and corn (DDGS₂) and wheat (DDGS₃) were studied and compared with a rapeseed meal (RSM). RSM and DDGS were characterized through in situ crude protein (CP) degradability. Nutrient digestibility was determined in sheep. Twenty‐four multiparous cows were used in a 4 × 4 Latin square design with 28‐day periods. Treatments included total mixed rations containing as primary protein sources RSM (control), DDGS₁ (D1), DDGS₂ (D2) or DDGS₃ (D3). RSM contained less rapidly degradable CP (fraction a), more potentially degradable CP (fraction b) and more rumen undegradable CP (UDP) than the three DDGS. In vivo digestibility of RSM organic matter was similar to DDGS. Calculated net energy for lactation (NE_L) was lower for RSM (7.4 MJ/kg DM) than for DDGS, which averaged 7.7 MJ/kg DM. Cows' dry matter intake did not differ between diets (21.7 kg/day). Cows fed D1 yielded more milk than those fed D3 (31.7 vs. 30.4 kg/day); no differences were found between control and DDGS diets (31.3 vs. 31.1 kg/day). Energy‐corrected milk was similar among diets (31.2 kg/day). Diets affected neither milk fat concentration (4.0%) nor milk fat yield (1.24 kg/day). Milk protein yield of control (1.12 kg/day) was significantly higher than D3 (1.06 kg/day) but not different form D1 and D2 (1.08 kg/day each). Feeding DDGS significantly increased milk lactose concentration (4.91%) in relation to control (4.81%). DDGS can be a suitable feed in relation to RSM and can be fed up to 4 kg dry matter per day in rations of dairy cows in mid‐lactation. However, high variation of protein and energy values of DDGS should be considered when included in diets of dairy cows.     

Quality and fatty acid profile of the milk of indigenous goats subjected to different local diets in Tunisian arid lands

The study tested the hypothesis that certain pastoral forages and olive by‐products, available in arid areas, may positively influence fatty acid composition and physicochemical properties of goat's milk. Thirty indigenous goats (body weight = 25.2 kg; age = 4.1 years) were allocated to three groups. During 60 days, the goats received ad libitum either dried olive leaves + Stipa tenacissima (group OL), khortane grass hay (group Ko) or oat hay (control diet, group OH). Milk samples were collected and analysed for total solids, fat, protein, lactose and ash content and fatty acid profile. Average milk yield did not statistically differ among groups. Milk total solids from OL group were higher in comparison with Ko and C groups (15.3, 14.7 and 14.5%, respectively; p < 0.05). Fat content was also higher for the OL group as compared to the other groups (5.44 vs. 5.01 and 4.66%, respectively, for Ko and OH). No significant differences were observed for the milk content of lactose, protein and ash. The percentage of saturated fatty acids of total milk fat was higher in OL and Ko groups compared to the C group (p < 0.001); the milk whereof was characterized by the highest percentage of monounsaturated (p < 0.01) and total unsaturated fatty acids. Milk fat of Ko and C groups showed significantly higher proportions of rumenic (CLA cis‐9 trans‐11) and vaccenic acids (C18:1 trans‐11) compared to OL milk. The feeding system based on Stipa tenacissima and dried olive leaves resulted in the milk lowest proportion of trans‐fatty acids and the highest proportion of polyunsaturated ω3‐fatty acids (p < 0.05).     

Pharmacokinetics of toltrazuril and its metabolites in pregnant and nonpregnant ewes and determination of their concentrations in milk,allantoic fluid,and newborn plasma

The objectives of this study were to determine the pharmacokinetics of toltrazuril and its metabolites in pregnant and nonpregnant ewes following a single oral dose and to determine the plasma concentrations of these compounds in milk, allantoic fluid, and newborn plasma. Eighteen healthy ewes were randomly divided into three groups (n = 6 each): pregnant ewes at 12–13 weeks of gestation (group A), nonpregnant ewes (group B), and pregnant ewes at 1–2 weeks before expected lambing date (group C). Ewes in all groups received a single oral dose of toltrazuril at 20 mg/kg body weight. In groups A and B, blood samples were collected at 1, 3, 5, 7, 9, 12, 15, 18 hr, every 6 hr to day 3, every 12 hr to day 7 and thereafter every 24 hr to day 14 post-toltrazuril administration. In group C, parturition was induced 24–36 hr after toltrazuril administration then milk, allantoic fluid, and newborn plasma samples were collected immediately after birth. Drug metabolites were assayed using ultra high-performance liquid chromatography–ultraviolet detection method (UHPLC-UV). The maximum concentration (C_max), area under the plasma concentration-time curve (AUC_0–t), AUC to 24 and 48 hr (AUC_0–24), and (AUC_0–48) were significantly higher in pregnant ewes. Longer apparent half-life (T_1/2), significantly higher apparent volume of distribution (Vd/F) and total clearance (Cl/F) were observed in nonpregnant ewes. The time to maximum plasma concentration (T_max), mean residence time (MRT) and elimination rate constant (K_el) were similar in both groups. The AUC_0–24 and AUC_0–48 were significantly higher in nonpregnant ewes. The AUC_0–t was significantly higher in pregnant ones. The ratio of plasma toltrazuril concentrations in ewes and toltrazuril concentrations in newborn lambs' plasma, allantoic fluid, and milk were 68%, 2.3%, and 5.3%, respectively. Results of this study showed that toltrazuril is well absorbed after a single oral dose in ewes with widespread distribution in different body tissues.     

过瘤胃氨基酸高能复合物对奶牛产奶量及乳成分的影响

为研究不同过瘤胃氨基酸高能复合物对奶牛产奶量及乳成分的影响,试验选择胎次(3～5胎)、产奶量、产犊日期相近,体重(600±20)kg健康荷斯坦泌乳高峰期奶牛24头,随机分为4组,每组6头。1组为对照组,饲喂牛场常规日粮;2、3、4组为试验组,分别在常规日粮基础上添加过瘤胃氨基酸高能复合物Ⅰ、Ⅱ、Ⅲ500 g/(d.头)。正式期60 d。结果表明:奶牛日粮中添加过瘤胃氨基酸高能复合物后,均可明显提高奶牛产奶量、乳脂率、乳蛋白率及乳中总干物质含量。尤其是复合物Ⅲ,添加效果最为理想,平均日产奶量、乳脂率、乳蛋白率及总干物质含量分别比对照组提高21.19%(P<0.05)、21.31%(P<0.05)、9.72%(P<0.05)和10.34%(P<0.05),平均日校正乳产量提高35.70%(P<0.05)。     

Finding best exotic breed proportion in crossbred lactating sheep kept under farmers’ conditions in Ethiopia determined by use of nested Legendre polynomials with limited data

ABSTRACT

The present study was conducted to estimate milk production performance and fit lactation curves for groups of ewes of Local and of Awassi crosses, with a variable blood level, reared under farmer’s environment. The Weigh-Suckle-Weigh method plus hand milking was used to estimate milk yield for ewes. A total of 466 observations from 115 ewes were used. Estimated least-squares adjusted means for the milk production over 120 days were 0.56?kg day^?1 (Local), 0.67 (<30% Awassi), 0.86 (30–50% Awassi), and 0.96 (>50% Awassi). Groups with 30–50% Awassi and >50% Awassi ewes produced significantly (p?<?0.05) more milk than Local ewes. Significant differences were observed between <30% Awassi and >50% Awassi crossbred groups. The best crosses (>50% Awassi) produced over 70% more milk than the local ewes which demonstrates the potential that exists in increasing milk production through the initiated crossbreeding programme with sheep in Ethiopia.     

Effects of Moringa oleifera silage on milk yield,nutrient digestibility and serum biochemical indexes of lactating dairy cows

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post‐seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.     

Changes in some blood parameters,milk composition and yield of buffaloes (Bubalus bubalis) during the transition period

In this study changes in hematochemical parameters, milk composition and yield were investigated in buffaloes during the transition period. A total of 93 buffaloes 113.9 ± 8.03 months old and 535 ± 50 kg average body weight were used. Parity was recorded, blood samples were collected from 80 days pre‐partum until 70 days post‐partum; milk samples were collected from 5 days to 70 days post‐partum. On serum samples, the values of non‐esterified fatty acids, β‐hydroxybutyrate, glucose, cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, gamma‐glutamyltransferase, urea, total proteins were evaluated. On milk, percentage of fat, protein and lactose, along with the somatic cell count (SCC), milk yield and daily milk production (DMP) were assessed. The peripartum period significantly (P ≤ 0.01) influenced all studied parameters with the exception of glucose. Milk fat percentage showed decreasing trend from 10 until 40 days post‐partum; DMP significantly (P ≤ 0.01) increased from 1 day post‐partum until 40 days post‐partum. Milk yield significantly (P ≤ 0.01) decreased in animals over the sixth lactation. Our results confirmed the importance of transit period in buffaloes. Blood parameters and milk composition alterations are crucial to predict the energy balance status of buffaloes in order to improve their management and feed intake during the transition period.     

Carry-over effects of body condition in the early pregnant ewe on peri-partum adipose tissue metabolism

This study evaluated the carry‐over effects of ewe body reserves during early pregnancy on peri‐partum adipose tissue metabolism. Forty‐nine multiparous ewes were divided in three categories according to their body condition score (BCS) at day 30 of pregnancy (BCS < 3, 2.5–2.75; BCS = 3; BCS > 3, 3.25–3.5). Live‐weight (LW) and BCS gains from 1st to 4th month of pregnancy were greater in ewes with BCS < 3 and 3 than in >3 animals. In contrast, in the last month of pregnancy, there was BCS decrease in all groups, although LW continued increasing. There were no differences in LW or BCS across ewe categories during this period. Peripheral leptin levels throughout the three last weeks of pregnancy were greater in ewes with BCS > 3 than in the rest, but this difference did not persist after lambing. Plasma metabolites related to energy metabolism, milk yield and lamb growth were not affected by ewe BCS in early pregnancy. Long‐chain saturated milk fatty acids (FA) (C16–C24) were greater in ewes with lowest BCS (<3 and 3). Ewes with greater BCS showed greater monounsaturated and lowest polyunsaturated milk FA content. Ewe post‐mating body reserves affect both pre‐partum leptinaemia and post‐partum milk polyunsaturated fatty acids content, but it had little effect on lamb performance.     

Effect of tannins and saponins in Samanea saman on rumen environment,milk yield and milk composition in lactating dairy cows

The objective of this study was to investigate the effects of tannins and saponins in Samanea saman on rumen fermentation, milk yield and milk composition in lactating dairy cows. Four multiparous early‐lactating dairy cows (Holstein‐Friesian cross‐bred, 75%) with an initial body weight (BW) of 405 ± 40 kg and 36 ± 8 day in milk were randomly assigned to receive dietary treatments according to a 4 × 4 Latin square design. The four dietary treatments were unsupplemented (control), supplemented with rain tree pod (S. saman) meal (RPM) at 60 g/kg, supplemented with palm oil (PO) at 20 g/kg, and supplemented with RPM at 60 g/kg and PO at 20 g/kg (RPO), of total dry matter (DM) intake. Cows were fed with concentrate diets at a ratio of concentrate to milk yield of 1:2, and chopped 30 g/kg of urea‐treated rice straw was fed ad libitum. The RPM contained condensed tannins and crude saponins at 88 and 141 g/kg of DM respectively. It was found that s upplementation with RPM and/or PO to dairy cows diets did not show negative effect on ruminal pH, blood urea nitrogen and milk urea nitrogen concentration (p > 0.05). However, supplementation with RPM resulted in lower ammonia nitrogen (NH₃‐N) concentration (p < 0.05). In addition, propionic acid and milk production increased while acetic acid, acetic to propionic ratio, methane production, methanogens and protozoal population decreased with RPM and/or PO supplementation. Furthermore, addition of PO and RPO in the diets increased milk fat while supplementation of RPM resulted in greater milk protein and Fibrobacter succinogenes numbers (p < 0.05). The population of Ruminococcus flavefaciens and Ruminococcus albus were not affected by any treatments. The findings on the present study showed that supplementation with RPM and RPO to diets of cows improved the rumen environment and increased milk yield, content of milk protein and milk fat.     

Adaptability and growth of Malpura ewes subjected to thermal and nutritional stress

A study was conducted to assess the effect of combined stresses (thermal and nutritional) on physiological adaptability and growth performance of Malpura ewes. Twenty-eight adult Malpura ewes (average BW 33.56 kg) were used in the present study. The ewes were divided into four groups, viz., GI (n = 7; control), GII (n = 7; thermal stress), GIII (n = 7; nutritional stress), and GIV (n = 7; combined stress). The animals were stall-fed with a diet consisting of 60% roughage and 40% concentrate. GI and GII ewes were provided with ad libitum feeding, while GIII and GIV ewes were provided with restricted feed (30% intake of GI ewes) to induce nutritional stress. GII and GIV ewes were kept in climatic chamber at 40°C and 55% RH for 6 h/day between 1000 and 1600 hours to induce thermal stress. The study was conducted for a period of two estrus cycles. The parameters studied were feed intake, water intake, physiological responses (viz., respiration rate, pulse rate, and rectal temperature), body weight, and body condition scoring (BCS) of ewes. Both thermal and combined stress significantly (P < 0.05) affected the feed intake, water intake, respiration rate, and rectal temperature. The feeding schedule followed in the experiment significantly (P < 0.05) altered the body weight and BCS between the groups. The results reveal that when compared with thermal stress, nutritional stress had less significant effect on the parameters studied. However, when both these stresses were coupled, it had a significant influence on all the parameters studied in these ewes. It can be concluded from this study that when two stressors occur simultaneously, the total cost may have severe impact on biological function.     

Effects of a Brown‐midrib corn hybrid on nutrient digestibility in wethers and on dry matter intake,performance, rumen and blood variables in dairy cows

The aim of the present trials was to determine the effect of an experimental Brown‐midrib (Bm) corn hybrid in relation to a commercial corn hybrid (Con) on digestibility in wethers and on dry matter intake (DMI), milk yield and milk composition in dairy cows. Digestibility of crude fibre (CF), neutral detergent fibre (NDFom) and acid detergent fibre (ADFom) were higher for Bm (CF Con: 57.8%; Bm: 67.2%; NDFom Con: 56.8%; Bm: 64.8%; ADFom Con: 52.0%; Bm: 63.9%), but concentration of net energy for lactation did not differ (Con: 6.4 MJ/kg DM; Bm: 6.3 MJ/kg DM). A total of 64 lactating German Holstein cows were assigned to one of the two dietary treatments Con or Bm according to milk yield, lactation number, days in milk and live weight. In Trial 1, cows were fed a total mixed ration consisting of 50% corn silage (Con or Bm) and 50% concentrate on dry matter (DM) basis. In Trial 2, the same animals were fed the respective silage for ad libitum intake and 5.3 kg of concentrate DM per animal per day. In Trial 1, DMI and milk‐fat content were decreased significantly for the Bm‐treatment (DMI Con: 22.5 kg/day; Bm: 21.5 kg/day; milk fat Con: 3.8%; Bm: 3.3%). In Trial 2, milk yield and fat‐corrected milk (FCM) were increased significantly, whereas milk‐fat% was decreased significantly (milk yield Con: 25.8 kg/day; Bm: 29.4 kg/day; FCM Con: 27.2 kg/day; Bm: 29.6 kg/day; fat Con: 4.4%; Bm: 4.0%). Diets did not influence ruminal pH or temperature. Diets, furthermore, did not influence rumination in either trial. Additional research on digestibility and rumen fermentation should, however, be carried out using dairy cows at respective intake levels as trials with wethers cannot be transferred to high‐yielding ad libitum fed cows.     

Effect of vacuum level on milking efficiency, somatic cell counts (SCC) and teat end wall thickness in ewes of Greek mountain Boutsiko breed

The aim of this work was to determine the effect of vacuum level of machine milking on milk yield, milk composition, milking efficiency, somatic cells counts (SCC), and teat end thickness of the Greek mountain breed Boutsiko ewes. Seventy two ewes after a suckling period of 45 ± 5 days were divided into three equal groups of 24 animals for level of milk production, prolificacy and lactation number. The overall experiment lasted 14 weeks. All groups were milked with a pulsation rate of 120/min, pulsator ratio of 50/50, and three vacuum levels of 38, 44 and 50 kPa, respectively, were applied for the three groups. Every two weeks, in a.m. and p.m. milking, measurements were taken for machine milk (MM) and machine stripped milk (MSM), milk composition, SCC, milk emission characteristics (only in a.m. milking) and teat end wall thickness (TEWT) before and after milking. The results have shown that the lower vacuum level of 38 kPa increased (P < 0.05) the percentage of machine milk (82.9%). There were no significant differences among the groups for milk composition, milk flow rate and SCC, but there was a difference in log SCC (P < 0.05) between 38 and 50 kPa. The teat end wall thickness was lower at the lower vacuum level (38 kPa) after milking, and increased (P < 0.001) as the vacuum level was raised to 50 kPa. The findings of this study suggest that with a lower vacuum level of 38 kPa, the ewes are milked better than those with 44 or 50 kPa. Also, the irritation of teats is considerably reduced, while no differences were seen regarding the health of the udder.     

和田多胎红羊泌乳规律初步研究

本研究旨在探明和田多胎红羊泌乳规律,提高双羔成活率。选取6只产双羔和田多胎红羊母羊为试验动物,检测其产后1~28 d泌乳量、乳成分变化规律;测量产后第1天母羊乳房体尺指标,并与泌乳量进行相关性分析。结果显示,和田多胎红羊产后1~28 d总泌乳量为29.87 kg,平均每日泌乳量为1.07 kg,泌乳量在第1~3天上升速度最快,在第21天达到峰值1.23 kg,泌乳曲线方程为：y=537t^0.477e^-0.033t;乳脂、非脂乳固体、密度、乳糖、固形物、蛋白质指标在和田多胎红羊母羊产后1~3 d快速下降,7~28 d趋于稳定,且6项指标第1天与第7、14、21、28天均差异极显著（P<0.01）;和田多胎红羊母羊产后第1天与第14、21、28天的泌乳量之间相关性不显著（P>0.05）,产后第2天与第28天的泌乳量相关性不显著（P>0.05）,其他均显著相关（P<0.05）;母羊产后第1、2、3、7天泌乳量与乳房宽呈显著相关（P<0.05）,母羊产后第14、21、28天泌乳量与乳房体尺指标相关性不显著（P>0.05）。以上研究结果为和田多胎红羊新类群种质特性、选育、饲料配制、羔羊早期断奶等提供理论依据。