Sixteen Boer and 16 Spanish (Span) yearling wethers were used, with eight of each breed in different initial body condition (IBC; High and Low). Initial BW was 40, 25, 29, and 22 kg (SE = 1.4) and body condition score (BCS; 1 = extremely thin and 5 = very obese) was 3.9, 2.4, 3.6, and 2.7 (SE = 0.12) for Boer-High, Boer-Low, Span-High, and Span-Low, respectively. There was one wether per breed x IBC treatment in each of eight 0.4-ha grass/forb pastures. Wethers in four control (Con) pastures were not supplemented with concentrate, whereas those in supplement (Sup) pastures received 0.9% BW (DM basis) of concentrate. The experiment was 126 days, with four periods 39, 28, 37, and 22 days in length. Forage mass was 2466, 2496, 3245, and 2495 kg/ha for Con and 2226, 2378, 3100, and 2724 kg/ha for Sup in periods 1, 2, 3, and 4, respectively (SE = 199.0). The difference in intake of digested OM between breeds was much greater with than without supplemental concentrate (485 and 741 g/day for Boer and 413 and 561 g/day for Span without and with supplementation, respectively; SE = 23.2). In accordance, supplementation increased (P < 0.05) ADG by Boer but not Span wethers (6, 32, 82, and 51 g for Boer-Con, Span-Con, Boer-Sup, and Span-Sup, respectively; SE = 13.1). There was a trend (P = 0.070) for greater ADG by Low vs. High IBC wethers (56 vs. 30 g; SE = 0.4), in agreement with overall greater (P < 0.05) total DM intake relative to BW by Low IBC wethers (3.16 and 2.78% BW; SE = 0.065). However, converse to the breed comparison, IBC and supplement treatment did not interact in ADG. Grazing time was less (P < 0.05) with than without supplementation (5.8 vs. 6.9 h; SE = 0.22) and greater (P < 0.05) for Boer vs. Span in period 1 (8.0, 6.9, 6.3, and 7.2 h for Boer and 4.7, 5.9, 5.7, and 6.4h for Span in periods 1, 2, 3, and 4, respectively; SE = 0.45), although IBC did not influence grazing time (6.2 and 6.6 h for High and Low, respectively; SE = 0.22) despite the difference in ADG and greater total DM intake relative to BW. In conclusion, supplementation increased ADG by Boer but not Spanish wethers and lessened grazing time, low IBC resulted in compensatory growth with increased DM intake relative to BW and ADG without affecting grazing time, and supplementation interacted with breed though not IBC. (C) 2015 Elsevier B.V. All rights reserved.

Effects of forage conditions with different stocking rates on performance and grazing behavior of goats could vary with animal physiological state, as influencing nutrient demand and usage. Therefore, Boer goat does nursing two kids (D; 1 month after kidding), growing wethers (G; 4 month initial age), and yearling wethers (Y; 14 month initial age) grazed 0.4-ha grass/forb pastures, with one animal per type in each pasture (four per stocking rate; SR) for a low SR and two for the high SR. The experiment started in late spring and was 114 days in length, with four periods of 33, 28, 30, and 23 days (P1, P2, P3, and P4, respectively). Data were analyzed by mixed models with a repeated measure of period. Forage mass was 2517, 2433, 2506, and 2452 kg/ha for the low SR and 2680, 1932, 1595, and 1393 kg/ha for the high SR in P1, P2, P3, and P4, respectively (SE=335.1). Botanical composition of the diet determined from n-alkane concentration in simulated grazed forage samples and feces was similar among animal types (P>0.10). Likewise, chemical composition of forage samples did not differ between animal types (P>0.10), with average dietary levels of 11% CP and 53% NDF. Digestibility of OM, determined from the concentration of the n-alkane hentriacontane (C31) in forage samples and feces, was the greatest for growing wethers (P<0.05; 63.5%, 67.2%, and 62.0% for D, G, and Y, respectively) and greater (P<0.05) for the low than high SR (66.1% vs. 62.3%). Intake of ME estimated from digestibility and fecal output was 1015, 855, and 692 kJ/kg BW0.75 for D, G, and Y, respectively (SE=57.4) and greater for the low than high SR in P1 (1204, 789, 682, and 445 for high SR and 1732, 767, 683, and 531 kJ/kg BW0.75 for low SR in P1, P2, P3, and P4, respectively; SE=93.5). There was an interaction (P<0.05) between animal type and period in ADG (13, −12, −44, −8, 83, 25, −28, 73, 127, 51, −43, and −7 g; SE=21.5) and time spent grazing (7.5, 5.3, 7.4, 8.6, 78.6, 5.6, 10.0, 9.1, 4.8, 5.9, 8.4, and 9.5 h for D-P1, D-P2, D-P3, D-P4, G-P1, G-P2, G-P3, G-P4, Y-P1, Y-P2, Y-P3, and Y-P4, respectively; SE=0.88). Rate of ME intake was greater (P<0.05) for D vs. G and Y (49.5, 21.9, and 33.9 kJ/min for D, G, and Y, respectively; SE=5.68) and differed (P<0.05) among periods (57.5, 45.3, 24.8, and 12.9 kJ/min in P1, P2, P3, and P4, respectively; SE=5.17). In conclusion, with this forage of moderate nutritive value, levels of forage mass above 1400 kg/ha would not be of benefit to performance of meat goats regardless of physiological state with different nutrient requirements.

Boer (BG) and Spanish goat (SG) and Rambouillet sheep (RS) wethers, ≥2.5yr of age, consumed grass hay ad libitum (AL) or in restricted amounts (RI). Initial BW was 50, 74, and 40kg for BG, RS, and SG, respectively. Intake of ME was 276, 230, and 281kJ/kgBW0.75 for BG, SG, and RS (SE=10.2) and 209 and 316kJ/kgBW0.75 for RI and AL, respectively (SE=7.7). Change in BW was lowest (P<0.05) among animal types for RS (−0.18, −0.29, and −0.14kg/day for BG, RS, and SG, respectively). Digestibility of NDF was similar among animal types. Total energy expenditure (EE) in kJ/kgBW0.75 was greatest (P<0.05) among animal types for BG (363, 335, and 335kJ/kgBW0.75 for BG, RS, and SG, respectively) and similar between levels of intake. Energy expenditure in MJ/day by the portal-drained viscera (PDV) (1.43, 1.25, and 1.17MJ/day; SE=0.118) and liver (1.16, 1.14, and 1.08MJ/day; SE=0.149) was similar among animal types. Both PDV (1.44 vs. 1.12MJ/day) and liver EE (1.50 vs. 0.76MJ/day) were greater (P<0.05) for AL vs. RI. Net fluxes of ammonia N across the PDV (3.1, 2.4, and 3.0g/day, SE=0.50; 2.9 and 2.7g/day, SE=0.34) and liver (−4.1, −3.5, and −3.8g/day for BG, RS, and SG, respectively (SE=0.63); −4.3 and −3.2g/day for AL and RI, respectively (SE=0.48)) were similar among animal types and between levels of intake. Net flux across the PDV of UN was greatest among animal types (P<0.05) for RS (−4.0, −1.4, and −3.6g/day for BG, RS, and SG, respectively) and similar between intake levels (−3.5 and −2.5g/day for AL and RI, respectively; SE=0.47). Net flux of UN across the liver was similar among animal types (3.1, 3.3, and 5.2g/day for BG, RS, and SG, respectively; SE=1.34) and between intake levels (5.2 and 2.5g/day for AL and RE, respectively; SE=1.02). In conclusion, some findings indicate that with limited nutritional planes of this experiment, sheep were less able to reduce EE than goats, which may have involved differences in extra-splanchnic tissue metabolism. Likewise, N recycling appeared less extensive for sheep vs. goats, but to a magnitude less than to impact fiber digestion.

Boer goat (BC). Spanish goat (SG), and Rambouillet sheep (RS) wethers, >= 2 yr of age, were used in a crossover experiment with 28-day periods. Diets were ad libitum consumption of wheat straw alone (CON) or with a 90% soybean meal. 10% molasses supplement given at 0.22% BW (SBM). Initial BW was 35, 55, and 32 kg for BG, RS, and SG, respectively. NDF digestibility was similar among animal types and between diets. BW change tended to be lowest for RS (-92, -158, and -107 g/day for BG, RS, and SG, respectively; SE = 22.6). ME intake was similar among animal types (244, 230, and 259 kJ/kg BW(0.75) for BG, RS, and SG, respectively; SE = 16.6) and greater (P < 0.05) for SBM vs. CON (320 vs. 168 kJ/kg BW(0.75)). Total energy expenditure (EE) was greater (P < 0.05) for RS than for BG (362. 415, and 402 kJ/kg BW(0.75) for BG, RS, and SG, respectively) and for SBM vs. CON (413 vs. 374 kJ/kg BW 35). EE by the portal-drained viscera (PDV) (1.34, 1.33, and 1.17 MJ/day; SE = 0.122) and liver (1.48, 1.44, and 1.32 MJ/day; SE = 0.133) was similar among animal types. Liver EE was greater (P < 0.05) for SBM vs. CON (1.60 vs. 1.22 MJ/day), but PDV EE was similar between diets. Net fluxes of ammonia N (AMN) and urea N (UN) across the PDV (AMN: 3.4, 2.4. and 3.2 g/day (SE = 0.69); UN: -5.2, -3.3, and -4.6 g/day (SE = 1.19)) and liver (AMN: -3.6, -3.2, and -4.3 g/day (SE = 0.78): UN: 7.6, 4.8. and 4.2 g/day for BG, RS. and SG, respectively (SE = 1.17)) were similar among animal types. In conclusion, the magnitude of any difference in N recycling among animal types was less than necessary to affect fiber digestibility. Nonetheless, some findings suggest a lesser ability of sheep to modify metabolic functions to cope with limited nutritional planes elicited by feeding crop residue-based diets, perhaps relating to metabolism by extra-splanchnic tissues. (C) 2011 Elsevier B.V. All rights reserved.

Beker, A., Gipson, T.A., Puchala, R., Askar, A.R., Tesfai, K., Detweiler, G.D., Asmare, A. and Goetsch. A.L., 2009. Energy expenditure and activity of different types of small ruminants grazing varying pastures in the summer. J. Appl. Anim. Res., 37: 1-14.Objectives were to determine the activity energy cost for different types of goats as well as a breed of sheep and to evaluate methods of prediction. Eight animals each of yearling Angora doeling goats, yearling Boer wet her goats, yearling Spanish wether goats and Rambouillet wether sheep slightly more than 2 yr of age were used. Two animals of each type were randomly allocated to one of the four pastures 9.3, 12.3, 4.6 and 1.2 ha. in area. Forage conditions varied markedly among pastures. The experiment was conducted in the summer with three periods, 30, 26 and 26 d in length. Energy expenditure (EE) was estimated from heart rate (HR) on pasture and EE:HR for each animal determined in a calorimetry system. A leg position/ movement monitoring system and a GPS collar with position and movement sensors were used to estimate distance traveled and time spent grazing/eating, resting while lying, resting while standing and walking without grazing/eating. EE attributable to activity (EEa%), expressed as a percentage of the ME requirement for maintenance plus activity in confinement, was determined based on total EE, BW and ADO. ADG was similar among animal types. Distance traveled was affected by an interaction (P<0.00 between animal type and period (Angora goats: 2.98, 2.33 and 2.47; Boer goals: 3.17, 3.46 and 2.68; Spanish goats: 2.85, 5.28 and 3.30; sheep: 3.04, 3.43 and 2.25 km in periods 1, 2 and 3, respectively (SE = 0.423). Time spent grazing was lowest among animal types (P<0.05) for Angora goats (4.3, 8.4, 7.8 and 6.8 h/day) and time spent walking without grazing was lower (P<0.05) for Angora goats and sheep than, for Boer goats.(1.7, 2.4, 2.1 and 1.2 h/day for Angora goats, Boer goats, Spanish goats and sheep, respectively). Total EE was affected by an interaction (P<0.05) between animal type and period (Angora goats: 5.59, 5.55, and 5.16; Boer goats: 9.63, 10.92 and 8.55; Spanish, goats: 6.73, 8.17 and 7.02; sheep: 12.54, 11.84 and 12.93 MJ/ day in periods 1, 2, and 3, respectively (SE = 0.442). EEa% was affected by an interaction (P<0.05) between animal. type and period (Angora goats: 15.7, 17.4 and 15.1; Boer goats: 59.7, 67.4 and 34.4; Spanish goats: 46.2, 61.7 and 41.6; sheep: 22.3, 11.8 and 21.9% in periods 1, 2 and 3, respectively (SE = 6.07). EEa% of goats was predicted with moderate accuracy (R-2 = 0.40-0.41) and without bias from estimates of 5.7.9 and 5.05%/h spent grazing/eating and grazing/eating plus walking, respectively, determined in a companion experiment.; however, these methods were not suitable for sheep.

Sixteen Boer and 16 Spanish multiparous does were used to determine how stocking rate (SR), breed and stage of production influence energy expenditure and behavioral activities on pasture and to develop a simple method of predicting energy used for activity. The experiment began lit late spring at an average of 24 d after kidding. Litter size was two and kids were Boer and Spanish. Two does of each breed resided in eight 0.5-ha grass/forb pastures. There were five periods, 56, 60, 63, 64 and 73 d in length, corresponding to mid-lactation, early post-weaning, the late dry period, early gestation and mid-gestation. During period 1 and the first part of period 2, two additional does with kids of each breed grazed in four High SR pastures, with other pastures designated as Low SR. Because of low available forage mass in period 3, grass hay was offered for ad libitum consumption in periods 3-5 and a concentrate supplement was provided in periods 4 and 5. Energy expenditure (EE) was estimated from heart rate (HR) on pasture and EE:HR for each doe determined in a calorimetry system. A leg position/movement monitoring system and a GPS collar with position and movement sensors were used to estimate distance traveled and time spent grazing/eating, resting while lying, resting while standing and walking without grazing/eating. EE attributable to activity (EEa%), expressed as a percentage of the ME requirement for maintenance plus activity in confinement, was determined based on total EE, estimated milk production and doe B Wand ADG. Forage DM mass in the middle of periods was 696, 246, 125 and 196 kg / ha for the High SR and 1362, 967, 4 79 and 610 kg I ha for the Low SR in periods 1, 2, 3 and 4, respectively. Kid ADG at weaning after 73 d was lower (P<0.05) for the High us. Low SR (87 vs. 112 g). Distance traveled was not influenced by SR or breed but varied among periods (3.54, 3.76, 3.09, 3.08 and 4.10 km / d in periods 1, 2, 3, 4 and 5, respectively; SE = 0.193). Time spent grazing/eating tended (P < 0.07) to be greater for Boer vs. Spanish does (7.9 vs. 6.7 h/d) and differed among periods (8.0, 7.8, 7.6, 5.3 and 8.0 h/day in periods 1, 2, 3, 4 and 5, respectively; SE = 0.72). Total EE was greater (P<0.05) for Boer than for Spanish does (13.4 vs. 11.4 MJ/d) and differed among periods (13.5, 11.6, 11.7, 11.8 and 13.4 MJ/day in periods 1, 2, 3, 4 and 5, respectively; SE = 0.41). Likewise, predicted ME intake was greater (P<0.05) for Boer vs. Spanish does (14.2 vs. 12.2 MJ/d) and varied with period (16.1, 10.6, 12.8, 12.6 and 14.0 MJ/day lit periods 1, 2, 3, 4 and 5, respectively; SE 0.47). EEa% was not influenced by SR, breed or period, averaging 49%. Behavioral activities were not highly related to EEa%, although no-intercept regressions against time spent grazing/eating and grazing/eating plus walking indicated an increase in EEa% of 5.79 and 5.05%/h, respectively. In conclusion, although EEa% was not affected by treatments of this experiment or highly related to behavioral activities monitored, it represents a sizeable cost of energy deserved of further study.

Female Alpine goats, 18 approximately 17 months of age (yearling) and 18 approximately 5-month-old (growing), were used in an experiment to determine effects of animal age, urea dose (100, 130, and 160 mg/kg BW), and time without feed and water (shrink; 0, 16, and 24 h) on urea space (US) estimates. A 20% (w/v) urea solution was infused into a jugular vein, with blood sampled before infusion and every 3 min to 21 min. BW was 49.8, 47.4, and 47.0 kg for yearlings and 26.1, 24.6, and 23.9 kg for growing animals after 0, 16, and 24 h shrinks, respectively (S.E. = 0.80). Time of urea equilibration with body water, determined by a grafted polynomial quadratic-linear model, was affected by a dose x age x shrink interaction (P < 0.05); yearling means did not differ (ranging from 7.3 to 10.8 min), although those for growing animals were greater (P < 0.05) for 0 h: 130 mg (13.0 min) and 24 h: 130 mg (13.2 min) compared with 24 h: 100 mg (7.6 min) and 16 h: 130 mg (7.1 min). Based on these times, 12-min samples were used to determine urea space. Urea space was influenced by an age x shrink interaction (P < 0.05), being similar among shrink times for yearlings (17.8, 18.8, and 18.9 kg) and greater (P < 0.05) for growing animals after 0 than 24 h shrink (12.9, 11.3, and 10.0 kg for 0, 16, and 24 h, respectively). Hemoglobin concentration in plasma, as an index of hemolysis, was lower (P < 0.05) for growing than for yearling animals (1.16% versus 1.86%), lowest among doses (P < 0.05) for 100 mg (1.05, 1.74, and 1.75% for 100, 130, and 160 mg, respectively), and highest among shrink times (P < 0.05) for 24 h (1.46, 1.42, and 1.61 % for 0, 16, and 24 h, respectively). In conclusion, effects of and interactions involving some of the factors studied and high variability in the time of urea equilibration with body water indicate that, regardless of the particular urea space procedures chosen, relatively high numbers of observations are warranted. (c) 2006 Elsevier B.V. All rights reserved.

Eleven yearling meat goat wethers (7/8 Boer and 1/8 Spanish) were used in a 16-week experiment to determine effects of different levels of nutrient restriction and a maintenance level of intake after a severe restriction on energy expenditure (EE). Dehydrated alfalfa pellets were fed throughout the experiment. During the first 4 weeks for adaptation, wethers were fed near maintenance. In weeks 5 to 10, six wethers were fed at approximately 60% of the maintenance level and in weeks 11 to 16 were again fed near maintenance (L-H). The other five wethers were fed at approximately 80 and 60% of maintenance in weeks 5 to 10 and 11 to 16, respectively (M-L). Body weight and EE were measured on the last day of most weeks, with EE determined from heart rate and the previously determined ratio of EE to heart rate for each wether. Body weight differed among weeks but not between treatments (41.0, 41.5, 39.7, 39.5, 38.0, 37.2, 38.0, 37.5, 37.8, 38.8 and 30.3 kg for L-H (SE=1.29) and 38.6, 38.2, 37.2, 37.2, 36.6, 35.0, 36.6, 36.7, 35.9, 35.7 and 36.9 kg (SE=1.41) for M-L in wk 4, 5, 6, 7, 9, 10, 11, 12, 13, 15 and 16, respectively). Energy expenditure, expressed relative to BW at the end of the adaptation period, was 362, 366, 322, 280,262,260,259, 331, 331 and 335 kJ/kg BW0.75 (SE=11.4) for L-H and 342, 378, 306, 301, 282, 276, 288, 263, 253 and 254 kJ/kg BW0.75 (SE=14.8) for M-L in weeks 4, 5, 6, 7, 9, 10, 11, 12, 13 and 15, respectively. Retained or recovered energy was different (P < 0.05) from 0 for L-H in weeks 4, 5, 6, 11, 12, 13 and 15 (65, -101, -56, -14, 4, 6, 192, 120, 121 and 117 kJ/kg week 4 BW0.75; SE=15.7) and for M-H in weeks 4, 5, 9 and 10 (92, -47, 25, 29, 49, 55, -14, 11, 21 and 20 kJ/kg week 4 BW0.75 in weeks 4, 5, 6, 7, 9, 10, 11, 12, 13 and 15, respectively; SE=17.3). In conclusion, meat goats can markedly reduce EE in response to limited feed intake, with nonlinear change as time advances.

1. Four breeding groups of Rhode Island Red and White Leghorn domestic fowl (RIR (female) x RIR (male), RIR (female) x WL (male), WL (female) x RIR (male) and WL (female) x WL (male)) were compared for fertility, hatchability, and their post-insemination sustainability, egg weight loss during incubation and uncovered yolk in abdominal cavity of dead in shell in order to understand the problems associated with the RIR breed in these respects.2. Crossing RIR (female) with WL (male) or in reverse sex combinations did not improve fertility in comparison to pure RIR chickens and all these groups were less fertile than the pure WL.3. Unlike fertility, hatchability in RIR improved with the change to either sex partner of the WL breed but the WL (female) x RIR (male) combination was similar to the pure WL (97.72 and 97.12%, respectively). In contrast, crossing RIR (female) with WL (male) resulted in an improvement (86.67%) as compared to pure RIR (76.67%) but still lower than the pure WL and WL (female) x RIR (male) cross.4. Egg weight loss during incubation was more (20.16%) in pure RIR as compared to RIR (female) x WL (male) (17.13%), followed by WL (female) x RIR (male) (10.28%) and pure WL (9.57%).5. There were more dead-in-shell embryos with yolks outside their abdominal cavity in pure RIR and their crosses as compared to pure WL breeds.6. Fertility was sustained for longer in WL than other combinations with post-artificial insemination using constant number of spermatozoa. Fertility after a week of insemination tended to decrease more rapidly than hatchability on a fertile egg basis.7. It is concluded that both sexes are responsible for the poor fertility in RIR but the female is responsible for poor hatchability and this poor performance is mainly due to greater egg weight loss during incubation.