[Show abstract][Hide abstract] ABSTRACT: 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 × 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 6.4 h 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.
Full-text · Article · Feb 2015 · Small Ruminant Research
[Show abstract][Hide abstract] ABSTRACT: Effects of the number of Boer goat wethers with initial age of 285 days (SEM = 5.1) and 34.4 kg body weight (SEM = 0.90 kg) per automated feeder and length and time of feeder access on feed intake, growth performance, and behavior were determined in a 10-wk experiment. Treatments were 6 and 12 wethers per 6 × 6 m pen and feeder with continuous access (Cont-6 and Cont-12, respectively); 2 and 4 wethers per feeder with 8 h/day access during daytime (Day-2 and Day-4, respectively); and 4 and 8 wethers per feeder with 16 h/day access at night (Night-4 and Night-8, respectively). Therefore, maximal potential feeder occupancy time per wether was 2 or 4 h/day. Dry matter intake was greater for continuous vs. restricted feeder access (P = 0.001) and for night vs. daytime access (P = 0.025) (2.04, 2.01, 1.45, 1.50, 1.92, and 1.76 kg/day), and feeder occupancy time per wether tended (P = 0.071) to be greater for continuous access (1.83, 1.55, 1.23, 1.34, 1.51, and 1.25 h/day for Cont-6, Cont-12, Day-2, Day-4, Night-4, and Night-8, respectively). Rate of dry matter intake (DMI) was similar among treatments. There were effects of continuous vs. restricted (P = 0.012) and day vs. night (P = 0.051) access on average daily gain (ADG), as well as a tendency (P = 0.078) for an interaction between time and length of restricted access (237, 252, 174, 207, 247, and 211 g for Cont-6, Cont-12, Day-2, Day-4, Night-4, and Night-8, respectively). The ratio of ADG:DMI was not affected by treatment other than a tendency for an interaction (P = 0.070) between time and length of restricted access (116, 126, 120, 138, 130, and 121 g/kg), although residual feed intake (RFI) was greater (P < 0.001) for continuous vs. restricted access (49, -25, -167, -257, -81, and -112 g for Cont-6, Cont-12, Day-2, Day-4, Night-4, and Night-8, respectively). In summary, continuous feeder access allowed high ADG, but resulted in relatively inefficient feed utilization as assessed by RFI. Restricting feeder access to daytime minimized DMI compared with continuous access, which was due to factors other than feeder occupancy time and rate of DMI; however, efficiency of feed utilization for daytime access based on RFI, particularly for Day-4, was high relative to continuous access. In conclusion, restricting feeder access influenced feed intake, growth performance, and behavior, with results impacted by time of access.
No preview · Article · Oct 2014 · Small Ruminant Research
[Show abstract][Hide abstract] ABSTRACT: Growing meat goats of 4 types (Boer and Spanish of both wethers and doelings) were used to evaluate conditions for a method of testing efficacy of electric-fence strand additions to barbed-wire fence used for cattle to also contain goats. Animals were allocated to 8 sets, with each set consisting of 5 groups. There was 1 goat of each of the 4 types in a group. One side of five 2.4- × 3.7-m evaluation pens consisted of barbed-wire strands at 30, 56, 81, 107, and 132 cm from the ground. Evaluation pens were adjacent to a pasture with abundant vegetation. Fence treatments (FT) were electrified strands (6 kV) at 15- and 43- (LowHigh), 15- and 23- (LowMed), 15- (Low), 23- (Med), and 43-cm (High), where Low, Med, and High abbreviations are for low, medium, and high heights from the ground, respectively. For adaptation, there were 4-wk and sequential exposures to evaluation pens: wk 1, no electric strands; wk 2, 1 strand at 0 kV; wk 3, LowHigh; and wk 4, LowHigh. There were 6 periods for measurements, each separated by 1 wk. During the 1-wk intervals on pasture, sets were exposed to 1 interval treatment without and another with 2 electric strands (6 kV) positioned next to supplement troughs, to potentially affect familiarity with electrified strands and influence subsequent behavior. All animal sets were used for measurements in period 1 in a completely randomized design (CRD). Four sets were also used in 4-wk subsequent measurement periods for a 5 × 5 Latin square (LS). All animal sets were exposed to the same FT in period 6 as in period 1. Behavior in evaluation pens was observed for 1 h with a video surveillance system in the 6 periods. There were no effects of gender and few and minor effects of preliminary and interval treatments. The percentage of animals that exited evaluation pens differed (P < 0.05) among FT, with the CRD approach in period 1 (25%, 47%, 38%, 66%, and 84%; SEM = 8.0) and with repeated measures in periods 1 and 6 (6%, 22%, 22%, 63%, and 81% for LowHigh, LowMed, Low, High, and Med, respectively; SEM = 4.9), and between breeds in periods 1 (34% and 70%) and 1 and 6 (28% and 50% for Boer and Spanish, respectively). For the LS approach, FT affected exit (31%, 23%, 16%, 35%, and 30%; SEM = 5.3) and breeds differed (P < 0.05), as well (12% and 43%). Exit decreased as period advanced (60%, 35%, 23%, 10%, and 8%, for 1, 2, 3, 4, and 5, respectively; SEM = 5.3). In conclusion, breed should be considered in the model being developed. A LS approach was not suitable, but a CRD experiment after these adaptation procedures appears promising.
No preview · Article · Sep 2013 · Journal of Animal Science
[Show abstract][Hide abstract] ABSTRACT: 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.
Full-text · Article · Jun 2013 · Livestock Science
[Show abstract][Hide abstract] ABSTRACT: Effects of creep grazing and stocking rate (SR) on forage selection and nutritive value of the diet of Spanish does with Boer × Spanish kids and Boer × Spanish does with 3/4 Boer–1/4 Spanish kids were determined in ten 0.4-ha pastures. There were four treatments, three involving SR and one creep grazing, with two animal groups for each treatment. Groups had 4 does with 8 kids for the low SR (L), 6 does with 12 kids for the moderate SR (M), and 8 does with 16 kids for both high SR (H) and creep grazing treatments (C). Kids of the C treatment also had access to similar 0.4-ha pastures that contained the leguminous tree mimosa (Albizia julibrissin Durazz) planted in rows. A direct observation and simulation method was used to characterize the diet selected by does and kids and obtain representative samples. The latter were evaluated for nutritive value based on CP, NDF, ADF, and ADL concentrations and in vitro true DM digestibility (IVTDMD). There were no effects (P > 0.05) of stocking rate or animal type on botanical composition of the diet selected or nutritive value. Thus, when exposed to similar forage conditions, botanical composition and nutritive value of the diet selected by does and kids were similar. Although, when kids had access to a creep grazing area, mimosa tree leaves were 53% of the diet for improved nutritive value compared with grazing in the base pasture without mimosa trees (i.e., 21.9 vs. 19.8% CP, 34.1 vs. 53.8% NDF, 21.4 vs. 27.5% ADF, and 85.7 vs. 79.9% IVTDMD).
No preview · Article · Jan 2013 · Small Ruminant Research
[Show abstract][Hide abstract] ABSTRACT: Goats and sheep often graze together and guardian dogs are commonly used for protection from predators. The objective of this experiment was to characterise how goats, sheep and guardian dogs interact spatially when grazing the same pasture by use of global positioning system (GPS) collars as an unobtrusive means of behaviour monitoring. In 2002 and 2003, three meat goats and two sheep in a group of 12 of each species were randomly chosen and, along with a guard dog, fitted with GPS collars. Minimum distance travelled between consecutive 30-min fixes and distance between any two animals at the same fix time were calculated using spherical geometry. In 2002, the dog travelled the least between fixes during the day but more at night than either goats or sheep. However, in 2003, there was not a significant species difference in distance travelled in 24 h or during the day or night. All species travelled significantly more during day than night but none were stationary at night. Distance amongst goats and between sheep tended to be greater during day than night; distance between goats and sheep was greater than the distance amongst goats or between sheep. Hence, goats and sheep interacted as two separate entities rather than as one large herd/flock. Distance between the dog and goats was closer than between the dog and sheep, indicating a clear preference of the dog for goats that could relate to a difference in previous exposure to the two species. In summary, based on these findings protection by a guardian dog would be greater for a small group of goats than sheep and much greater than for a mixed species group. Or, with a large group of grazing animals, the number of dogs required for a certain level of protection would rank goats < sheep < mixture of goats and sheep.
No preview · Article · Dec 2012 · Journal of Applied Animal Research
[Show abstract][Hide abstract] ABSTRACT: Twenty-four yearling Boer (87.5%) × Spanish wethers (32.5 ± 0.36 kg body weight) were used in a 32 d experiment to assess effects of frequency of feeding condensed tannin (CT)-containing Sericea lespedeza (SL; Lespedeza cuneata) on ruminal methane emission. Fresh SL (153 g/kg CT) was fed at 1.3 times the metabolizable energy requirement for maintenance every day (1SL), other day (2SL), fourth day (4SL), and eighth day (8SL), with alfalfa (Medicago sativa) offered at the same level on other days. Ruminal fluid for microbial assays was collected 1 d after SL feeding and at the end of the feeding interval (short and long interval samples, respectively). Dry matter intake was not affected by frequency of SL feeding. Daily ruminal methane emissions increased at a decreasing rate (Linear and Quadratic; P<0.01) as frequency of SL feeding decreased (6.3, 7.4, 10.5, 12.0 g/d for 1SL, 2SL, 4SL, and 8SL, respectively), but emissions on days when SL was fed were not affected by SL feeding frequency (6.3, 6.4, 6.7, 7.0 g/d, respectively). There were carryover effects of feeding SL on ruminal methane emissions. For example, with 8SL ruminal methane emission did not reach a maximum until day 5-6, or 4-5 days after SL was first fed. Energy in ruminally emitted methane relative to digestible energy intake increased linearly (P<0.05) as frequency of SL feeding decreased (49, 48, 66, 81 kJ/MJ for 1SL, 2SL, 4SL, and 8SL, respectively). The number of protozoa in the short interval sample was not affected by frequency of feeding SL (5.2, 5.3, 5.7, 6.5 × 105/ml), whereas the number in the long interval sample increased at a decreasing rate (Linear P<0.01; Quadratic P=0.02) as frequency of SL feeding decreased (6.5, 10.4, 18.4, 20.5 × 105/ml for 1SL, 2SL, 4SL, and 8SL, respectively). In vitro methane emissions (3 wk incubation in serum bottles for methanogens; indicative of methanogen presence and activity in ruminal fluid) were lower for short than for long samples (19.0 and 24.2 ml, respectively) and increased linearly (P<0.05) as frequency of SL feeding decreased (19.3, 19.3, 23.0, 24.8 for 1SL, 2SL, 4SL, and 8SL, respectively). In conclusion, the influence of CT containing SL on ruminal methane emission was immediate and short-lived, and the effect appeared attributable to activity of methanogenic bacteria and possibly ciliate protozoa.
No preview · Article · Jul 2012 · Animal Feed Science and Technology
[Show abstract][Hide abstract] ABSTRACT: Twenty-four yearling Boer × Spanish wethers were used to assess effects of different forages, either fresh (Exp. 1) or as hay (Exp. 2), on feed intake, digestibilities, heat production, and ruminal methane emission. Treatments were: 1) Sericea lespedeza (SER; Lespedeza cuneata), a legume high in condensed tannins (CT; 20% and 15% in fresh forage and hay, respectively), 2) SER supplemented with polyethylene glycol (SER-PEG; 25 g/d), 3) alfalfa (Medicago sativa), a legume low in CT (ALF), and 4) sorghum-sudangrass (Sorghum bicolor), a grass low in CT (GRASS). Experiments were 22 d, which included 16 d for acclimatization followed by a 6-d period for fecal and urine collection, and gas exchange measurement (last 2 d). Intake of OM was 867, 823, 694, and 691 g/d (SEM = 20.1) with fresh forage, and 806, 887, 681, and 607 g/d with hay for SER, SER-PEG, ALF, and GRASS, respectively (SEM = 46.6). Apparent total tract N digestion was greater for SER-PEG vs. SER (P < 0.001) with fresh forage (46.3%, 66.5%, 81.7%, and 73.2%; SEM = 1.71) and hay (49.7%, 71.4%, 65.4%, and 54.8% for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 1.57). Intake of ME was similar among treatments with fresh forage (8.24, 8.06, 7.42, and 7.70 MJ/d; SEM = 0.434) and with hay was greater for SER-PEG than ALF (P < 0.03) and GRASS (P < 0.001) (8.63, 10.40, 8.15, and 6.74 MJ/d for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 0.655). The number of ciliate protozoa in ruminal fluid was least for SER with fresh forage (P < 0.01) (9.8, 20.1, 21.0, and 33.6 × 10(5)/ml; SEM = 2.76) and hay (P < 0.02) (6.3, 11.4, 13.6, and 12.5 × 10(5)/ml for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 1.43). Methane emission as a percentage of DE intake was lower (P < 0.01) for SER vs. ALF and GRASS with fresh forage (6.6, 8.3, 9.4, and 9.2%; SEM = 0.64) and hay (4.3, 4.9, 6.4, and 6.7% for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 0.38). In summary, methane emission in this short-term experiment was similar between a legume and grass low in CT as fresh forage and hay. The CT in SER markedly decreased N digestibility and elicited a moderate decline in ruminal methane emission. Supplementation with PEG alleviated the effect of CT on N digestibility but not ruminal methane emission, presumably because of different modes of action. In conclusion, potential of using CT-containing forage as a means of decreasing ruminal methane emission requires further study, such as with longer feeding periods.
No preview · Article · Mar 2012 · Journal of Animal Science
[Show abstract][Hide abstract] ABSTRACT: 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
Full-text · Article · Feb 2012 · Small Ruminant Research
[Show abstract][Hide abstract] ABSTRACT: Forty-eight Boer goat doelings (10.4 ± 0.13 mo of age and 27.1 ± 0.98 kg in BW) were used in a 9-wk experiment to compare feeding value of deep-stacked (DS) and ensiled (EN) broiler litter. The broiler litter was processed for 82 d before use. Treatments were feeding 1% of BW (DM) 3:1 corn–soybean meal mixture and moderate-to-high-quality grass hay free choice (Cont-F); 1% of BW hay and the concentrate mixture free choice (Cont-C); 1% of BW hay, 1.1% of BW corn, and DS or EN free choice (DS-L and EN-L, respectively); and 1% BW hay and DS or EN free choice (DS-H and EN-H, respectively). Daily samples of DS and EN averaged 70.9 and 73.3% OM (DM basis), 21.8 and 23.2% CP, and 34.0 and 37.2% NDF, respectively. Total OM intake was less for DS-H and EN-H versus DL-L and EN-L broiler-litter treatments (P < 0.05), similar between DS-L and EN-L, and greater (P < 0.05) for EN-H than for DS-H (1,025, 1,199, 829, 952, 470, and 631 g/d for Cont-F, Cont-C, DS-L, EN-L, DS-H, and EN-H, respectively; SE = 64.0). There were similar differences (P < 0.05) in ADG (126, 234, 58, 75, -46, and -8 g; SE = 10.1) and ADG:DMI (118, 188, 60, 66, –84, and -11 g/kg for Cont-F, Cont-C, DS-L, EN-L, DS-H, and EN-H, respectively; SE = 12.7). In conclusion, feeding values of DS and EN for yearling meat goat doelings appear similar with moderate dietary levels, but with limited consumption of other feedstuffs, feeding value of EN may be greater.
No preview · Article · Dec 2011 · The Professional Animal Scientist
[Show abstract][Hide abstract] ABSTRACT: Twenty-three Boer (75%)×Spanish (25%) multiparous does, eight with ruminal cannula, grazed grass/legume pastures in different stages of production. Four cannulated and eight non-cannulated does were confined in a building at night and had pasture access from approximately 07:00 to 19:00h (Night); other animals had continual pasture access (Past). Data collection periods 15days in length were in late gestation (L-G; 137±5.2days), early lactation (E-L; 43±2.1days), late lactation (L-L; 97±1.1days), the dry period (Dry), and early gestation (L-G; 65±5.9days). Most does had a litter size of 2, and kids were weaned at 118±1.0days. Ingesta collected from cannulated does after rumen-evacuation averaged 19.9, 12.5, 14.7, 13.4, and 19.9% CP (SE=0.59) and 50.8, 59.2, 63.1, 61.4, and 38.1% NDF in L-G, E-L, L-L, Dry, and E-G, respectively; (SE=1.55). Kid ADG tended (P
No preview · Article · Sep 2011 · Livestock Science
[Show abstract][Hide abstract] ABSTRACT: Sixteen Boer goat doelings, 16 Spanish doelings, and 8 Angora doelings and 8 wethers, 283, 316, and 330 d of age initially (SEM = 5.0), respectively, were used to evaluate effects of nutrient restriction on heat energy (HE). During the first and second 10-wk phases, 8 animals of each breed were fed a 50% concentrate pelletized diet at a level adequate for maintenance and moderate energy accretion (CONT). Other animals were fed approximately 50% of these amounts in phase 1 relative to initial BW, followed by the greater level of feeding in phase 2 based on initial or actual BW when greater (REST). Average daily gain was 43, -20, 16, -78, 8, and -48 g in phase 1 (SEM = 5.0) and 26, 44, 50, 65, 27, and 32 g in phase 2 (SEM = 3.5) for Angora-CONT, Angora-REST, Boer-CONT, Boer-REST, Spanish-CONT, and Spanish-REST, respectively. Total HE was greater for CONT vs. REST in both phases (P < 0.001), greater in phase 1 for Angora than for Boer (P < 0.01) and Spanish (P < 0.01), and greatest (P < 0.01) in phase 2 among breeds for Angora [481, 347, 430, 356, 424, and 338 kJ/kg of BW(0.75) per day in phase 1 (SEM = 11.1), and 494, 479, 445, 397, 444, and 406 kJ/kg of BW(0.75) per day in phase 2 (SEM = 11.3) for Angora-CONT, Angora-REST, Boer-CONT, Boer-REST, Spanish-CONT, and Spanish-REST, respectively]. Equations describing the temporal pattern of HE (kJ/kg of BW(0.75) per day), expressed as a percentage of the wk-0 value and corrected for corresponding breed × week CONT means, in phase 1 were 95.8 ± 2.43 - (8.18 ± 1.144 × week) + (0.655 ± 0.1098 × week(2)) for Angora (R(2) = 0.58), 95.3 ± 2.63 - (4.34 ± 1.237 × wk) + (0.271 ± 0.1187 × wk(2)) for Boer (R(2) = 0.41), and 97.4 ± 2.21 - (4.69 ± 1.068 × wk) + (0.282 ± 0.1021 × wk(2)) for Spanish (R(2) = 0.53). Phase 2 equations were 78.9 ± 2.22 + (8.74 ± 1.036 × wk) - (0.608 ± 0.0095 × wk(2)) for Angora (R(2) = 0.60), 77.5 ± 2.10 + (3.30 ± 0.978 × wk) - (0.153 ± 0.0942 × wk(2)) for Boer (R(2) = 0.39), and 80.6 ± 2.50 + (4.50 ± 1.165 × wk) - (0.208 ± 0.1122 × wk(2)) for Spanish (R(2) = 0.43). These equations indicate that changes in HE in response to nutrient restriction and realimentation were more rapid and of greater magnitude in Angora vs. Boer and Spanish. The temporal pattern of decline in HE by Boer and Spanish during restriction was similar, but the subsequent rise with realimentation was slower and smaller for Boer. In conclusion, most appropriate methods of predicting change in the maintenance energy requirement during and after periods of limited feed intake may differ among breeds of goats.
[Show abstract][Hide abstract] ABSTRACT: Boer goat (BG), Spanish goat (SG), and Rambouillet sheep (RS) wethers, ≥2yr 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 32kg 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 −107g/day for BG, RS, and SG, respectively; SE=22.6). ME intake was similar among animal types (244, 230, and 259kJ/kg BW0.75 for BG, RS, and SG, respectively; SE=16.6) and greater (P
Full-text · Article · Jun 2011 · Small Ruminant Research
[Show abstract][Hide abstract] ABSTRACT: Angora wethers (48), approximately 6months of age and 15.7kg initial BW (SEM=0.38), were used to determine the effects of the level of feed intake and realimentation on mohair fiber growth and tissue gain. There were two 12 weeks phases in which dehydrated alfalfa pellets (18% CP and 48% NDF, DM basis) were fed. In phase 1, feed amounts were intended to provide ME adequate for 0, 15, 30, 45, 60, and 75g/day of tissue (non-fiber) gain and 0, 1.5, 3.0, 4.5, 6.0, and 7.5g/day of clean mohair fiber growth, respectively (L1, L2, L3, L4, L5, and L6, respectively), although actual levels were slightly greater; intake was ad libitum in phase 2. DM intake in both phases increased linearly (P
No preview · Article · Jun 2011 · Livestock Science
[Show abstract][Hide abstract] ABSTRACT: Two experiments were conducted to determine appropriateness of conditions in a method being developed for evaluating efficacy of different electric fence additions to cattle barb wire fence for goat containment. In Experiment 1, two 6×6 Latin squares (LS), each with 24 yearling Boer goat doelings previously exposed to electric fence, were conducted. After overnight fasting, groups of four doelings were placed in 2.4×2.4 m pens without forage. One pen side was five strands of four-point barb wire (non-electrified) at 31, 56, 81, 107 and 132 cm from the ground adjacent to a pasture with abundant vegetation. One LS had periods 2–3 days in length and the other 7 days. Electric fence treatments for each square were addition to barb wire fence of four electric fence strands 15, 28, 43 and 58 cm from the ground at low voltage of 4–4.5 kV (4S-LV); two strands at 15 and 43 cm and high voltage of 8.5–9 kV (2S-HV); two strands at 15 and 43 cm and low voltage (2S-LV); one strand at 15 cm and low voltage (1S-LH-LV); one strand at 43 cm and low voltage (1S-HH-LV) and one strand at 23 cm and high voltage (1S-MH-HV). Percentages of doelings exiting (6% and 4%) and shocked in 2 h (15% and 16% for 7 and 2–3 days, respectively) were low and did not differ between period lengths. The percentage of doelings exiting in 2 h was not affected by fence treatment. Period of squares affected (p90%. With the LS method the percentage of doelings exiting also was similar among fence treatments but was 75%, 70%, 40%, 70% and 75% for 2S-HV, 2S-LV, 1S-LH-LV, 1S-HH-LV and 1S-MH-HV, respectively. With a comparison involving doeling sets used in the LS, the percentage of doelings shocked was lower (p
No preview · Article · Jan 2011 · Journal of Applied Animal Research
[Show abstract][Hide abstract] ABSTRACT: Central performance testing of meat goats has increased in popularity recently, but minimum test duration has not been ascertained to assess accurately performance traits. This study was conducted to determine the minimum length of time required for accurate evaluation of growing Boer bucks for ADG, dry matter intake (DMI), DMI/BW0.75, and feed efficiency as assessed by ADG:feed intake and residual feed intake. Data were collected from 425 bucks enrolled in Langston University tests lasting 84 days from 2000 to 2009. Bucks averaged 111±25 days of age and 27±8kg BW at the beginning of the test, consumed a pelletized 50% concentrate diet ad libitum, and were weighed weekly. Daily feed intake was determined with Calan gates (American Calan, Inc., Northwood, NH) or automated MK3 FIRE feeders (Feed Intake Recording Equipment, Osborne Industries Inc., Osborne, KS). Weekly data of five performance traits were analyzed using the MIXED procedure of SAS with a repeated-measures model. Residual variance relative to that at 84 days (%) for the goats fed with Calan gates was 358, 293, 235, 193, 153, 127, 116, and 107% for ADG, 184, 173, 161, 149, 136, 123, 113, and 106% for DMI, 374, 317, 256, 203, 161, 137, 118, and 107% for DMI/BW0.75, 445, 320, 225, 162, 135, 124, 111, and 105% for ADG:feed intake, and 174, 154, 143, 128, 113, 107, 103, and 102% for residual feed intake at 28, 35, 42, 49, 56, 63, 70, and 77d, respectively. Residual variance relative to that at 84 days (%) for the goats fed with FIRE was 286, 221, 192, 174, 154, 134, 125, and 110% for ADG, 111, 113, 111, 112, 111, 107, 106, and 105% for DMI, 176, 155, 144, 130, 120, 110, 110, and 110% for DMI/BW0.75, 373, 258, 216, 171, 134, 119, 114, and 106% for ADG:feed intake, and 114, 101, 103, 95, 94, 92, 98, and 103% for residual feed intake at 28, 35, 42, 49, 56, 63, 70, and 77d, respectively. Under either Calan gates or FIRE feeding conditions, the duration of Boer buck performance tests could be decreased from the standard 84 to 63 days with little loss in accuracy.
No preview · Article · Jan 2011 · Small Ruminant Research
[Show abstract][Hide abstract] ABSTRACT: Twelve mature Angora does were used in a replicated 3 × 3 Latin square to determine effects of feeding level on energy utilization. Fiber growth and change in tissue (nonfiber) mass were determined in the first 4 wk of 6-wk periods, preceded by 14 or 18 d of adaptation. Determination of ME intake and gas exchange measures occurred in wk 4, followed by feeding near maintenance, then fasting in wk 5 and 6 to determine the ME requirement for maintenance (ME(m)). A 60% concentrate diet was fed at levels to approximate 100, 125, and 150% of assumed ME(m) [low, medium (med), and high, respectively]. Digestibilities and diet ME/GE were not affected by treatment with different amounts of feed offered and subsequent intake near ME(m). Heat energy during fasting (261, 241, and 259 kJ/kg of BW(0.75); SEM = 8.7) and efficiency of ME used for maintenance (71.6, 69.6, and 69.2%; SEM = 2.29) were similar among treatments, although ME(m) differed (P < 0.04) between med and high (365, 344, and 377 kJ/kg of BW(0.75) for low, med, and high, respectively; SEM = 10.3). Tissue gain was less (P < 0.01) for low than for the mean of med and high (MH; -0.6, 23.7, and 29.8 g/d), although clean fiber growth only tended (P < 0.09) to differ between low and MH (5.60, 6.57, and 7.36 g/d for low, med, and high, respectively; SEM = 0.621). Intake of ME was greater (P < 0.01) for MH than for low (6.87, 8.22, and 8.41 MJ/d for low, med, and high, respectively). Total heat energy was less (P < 0.02) for low vs. MH and tended (P < 0.07) to be greater for high than for med (6.03, 6.31, and 6.77 MJ/d); mobilized tissue energy was low but greater (P < 0.02) for low vs. MH (0.16, 0.01, and 0.04 MJ/d for low, med, and high, respectively). Efficiency of ME use for fiber growth was similar among treatments (17.2, 16.3, and 17.7% for low, med, and high, respectively; SEM = 1.61). In conclusion, efficiency of ME use for fiber growth was similar to the NRC recommendation regardless of feeding level, although ME(m) was decreased perhaps because of experimental conditions used. Energy appeared partitioned to fiber growth, but preferential usage was not complete possibly because energy metabolism for tissue accretion reached a plateau with the greatest feeding level.
No preview · Article · Oct 2010 · Journal of Animal Science
[Show abstract][Hide abstract] ABSTRACT: Twenty-four lactating and 13 nonlactating Alpine goats were used to determine effects of stage of lactation and dietary concentrate level on energy utilization. Diets comprising 60 or 20% concentrate (60%C and 20%C, respectively) were consumed ad libitum by lactating animals and at a level of intake near maintenance by nonlactating animals. Measurement periods were d 25 to 31 (early), 87 to 94 (mid), and 176 to 183 (late) of lactation. Eleven observations were made in early and mid lactation for each diet, and 8 and 7 were made in late lactation for the 60%C and 20%C diets, respectively. Efficiency of metabolizable energy (ME) use for maintenance (66.9, 71.4, and 61.1% for early, mid, and late lactation, respectively) and the maintenance ME requirement (479, 449, and 521 kJ/kg of BW(0.75) for early, mid, and late lactation, respectively) determined with nonlactating animals differed among stages of lactation. The efficiency of ME use for maintenance was similar between diets, but the maintenance requirement tended to be greater for the 60%C than for the 20%C diet (504 vs. 463 kJ/kg of BW(0.75)). The latter difference may have involved greater ME intake for the 60%C diet, resulting in a slightly greater difference between ME intake and total heat energy for the 60%C compared with the 20%C diet (11 vs. -8 kJ/kg of BW(0.75)). Intake of ME by lactating goats was greater for the 60%C than for the 20%C diet (18.6 vs. 16.3 MJ/d). Recovered energy in lactation from mobilized tissue tended to be greater for the 60%C than for the 20%C diet (8.44 vs. 6.55 MJ/d) and differed among stages of lactation (2.60, 1.59, and 1.13 MJ/d in early, mid, and late lactation, respectively). Recovered energy in tissue gain was similar among stages of lactation and between diets and was not different from 0. Efficiency of use of dietary ME for lactation differed among stages of lactation (59.5, 51.9, and 65.4% for early, mid, and late lactation, respectively) and tended to be greater for the 60%C than for the 20%C diet (64.2 vs. 54.9%). The efficiency of use of dietary ME for maintenance and lactation was similar among stages of lactation and was greater for the 60%C compared with the 20%C diet (64.3 vs. 60.9%). Predicted milk yield from National Research Council requirements was reasonably accurate. In conclusion, using data of nonlactating goats to study energy utilization for maintenance in lactation has limitations. Efficiency of energy use by lactating dairy goats consuming diets high in concentrate appears greater than that by goats consuming diets low in concentrate. Despite differences in nutrient requirement expressions, observations of this study support National Research Council recommendations of energy requirements of lactating dairy goats.
Preview · Article · Oct 2010 · Journal of Dairy Science
[Show abstract][Hide abstract] ABSTRACT: Thirty-six lactating Alpine does were used to determine effects of stage of lactation and level of feed intake on energy utilization. Twelve does were assigned to measurement periods in early, mid, and late lactation (wk 5, 13, and 27, respectively). For 6 does of each group, after ad libitum consumption of a 60% concentrate diet, feed intake was restricted to near the metabolizable energy (ME) requirement for maintenance (ME(m)) for 8 d followed by fasting for 4 d. For other does, fasting immediately followed ad libitum consumption. Intake of ME was similar among stages of lactation with ad libitum intake (22.1, 22.1, and 19.8 kJ/d in early, mid, and late lactation, respectively). The efficiency of ME use for maintenance determined with does fed near ME(m) averaged 81%. Fasting heat energy was greater for ad libitum consumption than for near ME(m) consumption [368 vs. 326 kJ/kg of body weight (BW)(0.75)] and was numerically lowest among stages in late lactation with near ME(m) intake (334, 350, and 295 kJ/kg of BW(0.75) in early, mid, and late lactation, respectively) and ad libitum consumption (386, 384, and 333 kJ/kg of BW(0.75) in early, mid, and late lactation, respectively). The efficiency of use of dietary ME for lactation was greater for consumption near ME(m) than for consumption ad libitum (67.9 vs. 58.6%) and with ad libitum consumption tended to decrease with advancing stage of lactation (63.9, 57.3, and 54.5% for early, mid, and late lactation, respectively). Estimated ME(m) was greater for ad libitum intake than for near ME(m) intake and was lowest during late lactation (429, 432, and 358 kJ/kg of BW(0.75) for near ME(m) intake and 494, 471, and 399 kJ/kg of BW(0.75) for ad libitum intake in early, mid, and late lactation, respectively). However, because of increasing BW as the experiment progressed, ME(m) (MJ/d) was similar among stages of lactation with both levels of intake. The efficiency of ME use for maintenance and lactation was similar among stages of lactation and greater with near ME(m) intake than ad libitum intake (77.1 vs. 67.7%). In conclusion, the ME(m) requirement (kJ/kg of BW(0.75)) of does in late lactation was less than in early and mid lactation. A marked effect of restricted feed intake subsequent to ad libitum consumption on estimates of efficiency of energy use for maintenance and lactation was observed compared with use of nonlactating animals. Level of feed intake can have substantial effect on estimates of energy utilization by lactating dairy goats.
Preview · Article · Oct 2010 · Journal of Dairy Science